Characterization and economic potential of the white...

392 Middle East Journal of Applied Sciences 4(2): 392-408, 2014

ISSN 2077-4613

Corresponding Author: Dr. EL-Wekeil, S.S., Geological Sciences Department, National Research Center, Cairo, Egypt.

E-mail: [email protected]

Characterization and economic potential of the white sandstones of the Naqus

Formation in Wadi Qena, northern Eastern Desert, Egypt

1EL-Wekeil, S.S. and

2Gaafar, F.Sh.

1Geological Sciences Department, National Research Center, Cairo, Egypt

2Egyptian Mineral Resources Authority

ABSTRACT

The Lower Paleozoic Naqus Formation rests unconformably on the peneplained Precambrian crystalline

rocks (mainly igneous and metamorphic rocks) of the Arabo- Nubian Shield and overlain unconformable by

shallow marine deposits of the Cenomanian transgression (Galala Formation) at the western margin of the

northern part of Wadi Qena. It consists predominantly of white silica sands and kaolinitic lenses. These

sediments were characterized and subjected to beneficiate in order to evaluate their economic potential. The

study focuses on investigation the mechanical, physical and chemical properties of these deposits in order to

assess their suitability for the production of glass and other economic products. The processes of investigations

included: 1- Laboratory work deals with chemical analysis, mechanical analysis and microscope studies. 2-

Beneficiation processes and tools include attrition scrubbing, hydrocyclone, low and high intensity

electromagnetic separator and shaking table. The silica sands of the Naqus Formation at Wadi Qena are exposed

on the surface, exposed in an area of approximately 450 km2, almost without overburden, so they are easily

mineable by open- pit- mining. The quantity of sand available is enormous and enough to support the glass

industry for many years. This silica sands are characterized by their whiteness and few impurities. However,

after simple beneficiation processes the percentage of impurities reduces with increase the silica (SiO2) ratio

(98.83%) and it become suitable for the production many types of glasses (cf. table ware, clear glass containers,

flat glass and colored glass). Kaolin represents a valuable co- product since its percent in the

oreapproximately11%. It can be used in ceramic, white cement, paper industry and as filler in rubber, paints and

plastics, in toothpaste, cosmetics, also as adsorbents in water and wastewater treatment and for Metakaolin

production which used in improvement of the quality of cement and concrete.

Key words: Egypt, Wadi Qena, Naqus Formation, glass sands, characterization and beneficiation of glass sands.

Introduction

Silica sands have got the most diversified use among all the non- metallic deposits. This is because of their

common occurrence worldwide, distinctive by useful physical characteristics such as hardness, chemical and

heat resistance as well as their low price. Industrial glass sands must contain a high proportion of silica (up to

99%) in the form of quartz. They are produced from both loose sand deposits and or by crushing weakly-

cemented sandstones. These glass sands are characterized by high degrees of purity, white color, and low levels

of deleterious impurities. The quality of the glass produced from silica sands depends essentially on their

chemical composition (mainly silica and alumina contents); grain- size composition generally in the range 0.5 to

0.1mm); particle shape (cf. elongation, flatness, roundness, angularity, etc); their contents of coloring oxides

particularly those of iron, chromium and titanium and the other contaminants such as clay, feldspar, mica,

organic matter. The needs of the Egyptian glass factories of white sand exceed1500 tons per year (Kamel et

al.,1997). The chemical, mechanical and physical characteristics of white sands (Silica sand deposits)were

studied by many authors for glass industry (e.g. Khalid, 1993; El-Bokle and Hasanein, 1993; El-Fawal, 1994;

Fathi, 2002; Salopek et al., 2004; Madanat et al., 2006; Bayat et al., 2007; Howard, 2008; Alnawafleh, 2009;

Sundarajam et al., 2009; Awadh, 2010; Mustafa et al., 2011;Odewale et al., 2013 and Ramadan, 2014).

About 16 localities containing high- grade silica sands have been identified in Egypt. The most important of

these are Wadi Qena and Wadi El- Dakhl (commercially known as El- Zaafarana), both are located in the

Eastern Desert, Gebel El- Gunnah (south Sinai) and El- Maadi, which is located in the Cairo suburbs (Fig. 1).

http://en.wikipedia.org/wiki/Toothpaste

http://en.wikipedia.org/wiki/Cosmetics

393 Middle East j. Appl. Sci., 4(2): 392-408, 2014

Fig. 1: Location map of glass sands in the main occurrences of Egypt.

Wadi Qena is one of the largest wadies in the Eastern Desert of Egypt. Glass sands constitute most of the

Lower Paleozoic Naqus Formation and are exposed in an area of approximately 450 km2at the western margin

of the northern part of Wadi Qena. The quantity of sand available is enormous. According to (Omayra, 2002),

probable reserves were estimated to be ~ 1 billion metric tons (Gt).

The lithostratigraphy, sedimentology and chronology of the Naqus sandstones located at the western margin

of the northern part of Wadi Qenawere extensively studied (e.g. Hassan, 1967; Said 1971 and 1990; Issawi and

Jux, 1982; Bandel et al., 1987; Klitzch et al., 1990; Abdallah et al., 1992;Issawi et al., 1999; Weissbrod, 2004;

and Wanas, 2011). Recently, Abou El-Anwar and El-Wekeil (2013) studied in detail the geochemistry,

mineralogy and petrography of the Naqus sandstones to shed more light on their provenance, tectonic setting

and depositional environments. They concluded that the sandstones are represented by quartz arenite being

highly enriched in quartz (88 to 95%). While kaolinite is the soleclay mineral constituent. These sandstones are

of adetrital origin, being inherited from felsic- granitic and reworked quartzose sediments and transported by

rivers to the basin of deposition.

No attention was paid to the economic potential of the silica sand deposits of the Naqus Formation which

form extensive exposures at the western margin of the northern part of Wadi Qena. Therefore, the aim of this

work is to investigate the mechanical, physical and chemical properties of these deposits in order to assess their

suitability for the production of glass and other economic products.

Lithostratigraphy:

In the Eastern Desert, north of Wadi Qena, the exposed Lower Paleozoic rock units are represented by the

Araba and Naqus formations (Wanas, 2011).The term Naqus Formation was given by Said (1971) for the

Paleozoic sandstones previously described by Hassan (1967) in Abu Durba area and assigned to the pre-

Carboniferous.

The study area lies between Longs. 32º 31′ 12″ - 32º 35′ 28″ E and Lats. 27º 46′ 55″ - 27º 55′ 55″ N

(Fig.2).The Naqus Formation rests unconformably on the peneplained Precambrian crystalline rocks (mainly

igneous and metamorphic rocks) of the Arabo- Nubian Shield. It occurs as scattered outcrops in a series of hills

and mesas and has a thickness ranging from ~22 m to ~120 m. The exposures have moderately steep to very

steep scarps and in places of the sandstones display a distinctive arabesque structure(Fig. 3).


Two stratigraphic sections have been measured in the study area, comprises a major part of the Naqus

Formation (Fig. 4). The first section (A) is ~106 m thick and the second section (B) measures ~120 m. The

Naqus sandstones have a similar lithological characteristic in both sections. They are commonly, white, fine- to-

medium grained, moderately- to- well- sorted, subangular to subrounded, moderately-hard to semi-friable and

occasionally contain coarse sand and granules. The sandstones are characterized by the presence of different

primary sedimentary structures such as planar- and troughcross- bedding and flat bedding. Kaolinitic lenses are

randomly distributed throughout the whole sequence especially at its upper part. The upper boundary of the

Naqus sandstones is absent in section (A), while section (B) is unconformably overlain by the shallow marine

sediments of the Cenomanian Galala Formation. The later is made up of ~15 m thick greenish yellow shale and

sandy marl intercalated with claystone.

Fig. 2: Landsat image of the northern Eastern Desert showing the location of the study area.

Fig. 3: Photograph showing the arabesque structure displayed by the glass sandstone at Wadi Qena.


Fig. 4: Lithostratigraphic columnar sections of the measured Naqus sandstone sequences modified after (Abou

El- Anwar and El- Wekeil, 2013).

Material and methodology:

Thirty- one samples representing the Naqus sandstones in the two sections (Fig. 2) were collected by

trenching. Beneficiation processes were conducted in the studied sands to improve their quality to meet the

Standard specifications of industrial glass sands and other economic products. The processes of investigations

included: 1- Laboratory work deals with chemical analysis, mechanical analysis and microscope studies. 2-

Beneficiation processes and tools include attrition scrubbing, hydrocyclone, low and high intensity

electromagnetic separator and shaking table.

1- Laboratorystudies:

X–Ray fluorescence was used to determine the chemical composition (major elements and Cr) of the

studied samples. The analysis was carried out for powdered (>74 μm) samples using an X- Ray fluorescence

equipment PW2404 with six analyzing crystals. The collected sandstone samples were subjected to grain- size

analysis following the procedure described by Ingram (1971). A representative dry samples weighing ~ 200 gm

were subjected to dry sieving using a set of sieves having opening diameters of 2.0, 1.0, 0.5, 0.25, 0.125, and

0.063 mm using a Ro- Tap shaker for 15 minutes as recommended by Pettijohn (1975).The obtained sand

fractions examined under the binocular microscope to study their physical characteristics and mineralogical

composition. The quartz grain surface microtextures of the studied sands were examined using SEM (Model;

QUANTA FEG 250). Ten representative samples of the studied sandstones were examined using SEM to

identify their surface microtextures. Approximately 20 grams of each sample were treated with HCl (30%) and

stannous chloride solution to get rid of carbonates and iron stains of quartz grains and then washed several times

with deionized water (cf. Krinsley and Doornkamp, 1973 and Madhavarajuet et al., 2009). Also, organic matter

was removed by using H2O2 (6%), (Madhavarajuet et al., 2009). Quartz grains (1.0 mm and 0.2 mm) were

examined using SEM to determine their mechanical and chemical weathering features. Approximately thirty

clean and dry quartz grains were randomly selected from the sand size fraction of each sample, which are

usually an adequate number to understand the variability present in a single sample (Madhavarajuet et al.,

2009).

Separation of the heavy minerals was carried out on the size fractions 0.25- 0.125 (fine sand) and 0.125-

0.063 mm (very fine sand) of selected samples collected from the two studied sections (Fig.2).These fractions


were first treated with HCl (10%) and stannous chloride solution in order to remove carbonates and iron oxide

coatings, followed by using bromoform solution (sp. gr. 2.85) according to the method adopted by Carver

(1971).The weight percentages of the obtained heavy fractions were calculated.

2- Beneficiation processes:

Beneficiation process of the studied Naqus sands was carried out using a variety of processes. The Attrition

Scrubber (Model; DENVER SALA SAED 50843-001) was used to increase the SiO2 content of the raw sands

and to reduce iron, chromium and titanium compounds, their contents of contaminants such as clay, organic

matter and heavy minerals to achieve the desired “cleaned particles”. The function of attrition scrubber is to

separate white sands from kaolinite by attrition. The grains are scrubbed primarily by the action of the slurry

particles impacting one another. The solid /liquid ratio must be 2:1, but becomes more effective when it reaches

3:1(solid 65 -75% and water 25 -35%).A representative specimens of the attrited sample (~ 200 gm) were

subjected to dry sieving using a set of sieves with opening diameters of 2.0, 1.0, 0.5, 0.25, 0.125, and 0.063 mm

using a Ro- Tap shaker was used for 15 minutes as recommended by Pettijohn (1975). The weight percent of

each sand fraction was calculated. The product of the attrited white samples must be treated in hydrocyclones.

Hydrocyclone (Model Hydrocyclone test RIG MK11 C700) was used to separate the white sands from

kaolinite.This was conducted on a pulp consisting of 20% solid and 80% water(solid/liquid ratio 1:4)under a

pressure of 60 psi. The underflow product contained sand while the overflow product consisted of sand and

kaolin. The overflow fraction was passed on another hydrocyclone having a diameter of 2 inches to separate the

coarse kaolin particles from the finer ones. This was followed by ahydrocyclone having a diameter of one inch

toproduce kaolin of a higher - quality. High- extraction magnetism was used as a beneficiation process to

upgrade high silica sand and kaolin in quality by removing the major contaminants such as iron and titanium-

bearing mineral impurities to meet the specifications required for industrial glass sands and kaolin. The process

involves selective filtering ferromagnetic (e.g. magnetite), paramagnetic (e.g. ilmenite), and/ or diamagnetic

(very low iron content) mineral particles from a slurry allowing the non-magnetic mineral particles to pass

through a magnetic matrix filter (e.g. zircon). This process was carried out on the studied sand samples using

(Laboratory Induced-Roll High intensity Magnetic Separator Carpco Model; MIH (13) 111-5). Shaking table

(Model; WILFLEY TABLE BALDOR Humphries) was used to improve silica sand grade and get rid of heavy

minerals. The process involves separation of heavy minerals from light minerals. It depends on the difference in

specific gravity between heavy and light minerals.

The chemical analysis, SEM and beneficiation processes were carried out in the Central Laboratories of the

Geological Survey in Cairo, Egypt.

Results and Discussions after laboratory studies:

A- Characterization:

1- Chemical analysis:

The results of the chemical analysis (Table1) for the original samples (Raw materials) revealed that the

proportions of SiO2 range from 87.56 to 95.11%; Al2O3 from 3.39 to 9.83%; Fe2O3 from 0.01 to 0.09%; TiO2

from 0.09 to 0.36%. Abou El- Anwar and El-Wekeil (2013) determined the Cr for some selective samples (S.

No. 2, 3, 6, 11, 13 and 18) for section (A) and (S. No. 4, 6, 8 and 10) for section (B). The chemical analyses

emphasized that the concentrations of Cr in the studied samples range between (1 to 2 ppm.).

2- Grain- size composition:

The weight percent of each sand fraction remained on the corresponding sieve was calculated. The obtained

data were presented graphically in the form of histograms (Fig.5).

The particle- size distributions in the investigated samples revealed that the grains of the studied sands are

well- sorted. More than 88 to 90% of the grains representing section (A) and section (B); respectively fall

mainly in the range of 1.0 to 0.125 mm (coarse, medium and fine sands). The very coarse and very fine sands

size constitutes minor proportions ranging from 5% to more than 9%.

3- Mineralogical Composition:

Table (2) shows that the studied sands are entirely composed of subrounded, monocrystalline quartz grains

(Plate 1: A and B) with a very few polycrystalline grains and rare heavy minerals. Commonly, the coarse grains

(0.5 mm) are rounded to well- rounded while the finer grains (0.125 mm) are subangular to angular. The


relatively impure sands are characterized by the presence of dark grey polycrystalline quartz grains as well as

low concentrations of heavy minerals, in contrast to clean white quartz grains.

Table 1: Chemical composition (%) of raw white sand samples prior to beneficiation (after Abou El-Anwar and El-Wekeil, 2013).

Section S.No. SiO2 Al2O3 TiO2 Fe2O3 MgO MnO CaO Na2O K2O P2O5 L.O.I

Sec

tion

A

1 91.12 6.54 0.16 0.01 0.01 0.01 0.24 0.01 0.01 0.03 1.54

2 90.35 7.34 0.23 0.01 0.01 0.01 0.29 0.01 0.01 0.03 1.43

3 87.56 9.83 0.27 0.01 0.01 0.01 0.22 0.01 0.01 0.04 1.71

4 91.13 6.51 0.30 0.07 0.04 0.01 0.08 0.01 0.01 0.08 2.01

5 94.96 3.47 0.11 0.04 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 0.01 1.23

6 94.15 4.12 0.10 0.03 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 0.01 1.46

7 94.51 3.81 0.09 0.05 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 0.01 1.35

8 94.83 3.53 0.14 0.04 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 0.01 1.25

9 92.34 5.33 0.19 0.04 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 0.01 1.89

10 94.64 3.75 0.10 0.03 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 0.01 1.32

11 94.95 3.49 0.09 0.03 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 0.01 1.32

12 94.71 3.55 0.18 0.05 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 0.01 1.27

13 95.05 3.39 0.14 0.03 < 0.01 0.01 < 0.01 < 0.01 < 0.01 0.01 0.20

14 94.15 4.01 0.21 0.04 < 0.01 0.01 0.07 < 0.01 < 0.01 0.01 1.42

15 93.91 4.10 0.16 0.05 0.04 0.01 0.09 < 0.01 < 0.01 0.05 1.51

16 93.41 4.35 0.18 0.06 0.04 0.01 0.08 < 0.01 < 0.01 0.07 1.72

17 93.75 4.25 0.17 0.04 0.03 0.01 0.18 < 0.01 < 0.01 0.04 1.56

18 93.85 4.05 0.16 0.04 0.03 0.01 0.11 < 0.01 < 0.01 0.05 1.48

Min. 87.56 3.39 0.09 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 0.01 0.20

Max. 95.05 9.83 0.30 0.07 0.04 0.01 0.29 0.01 0.01 0.08 2.01

Aver. 93.30 4.75 0.17 0.04 0.01 0.01 0.08 0.00 0.00 0.03 1.43

Sec

tion

B

1 93.35 4.53 0.20 0.09 0.03 0.01 0.12 < 0.01 < 0.01 0.07 1.43

2 93.05 4.70 0.22 0.07 0.03 0.01 0.14 < 0.01 < 0.01 0.05 1.64

3 92.63 4.95 0.10 0.05 0.03 0.01 0.15 < 0.01 < 0.01 0.03 1.67

4 89.87 6.65 0.34 0.05 0.01 0.01 0.16 < 0.01 < 0.01 0.06 2.34

5 90.12 6.54 0.35 0.04 0.01 0.01 0.16 < 0.01 < 0.01 0.06 2.22

6 92.89 4.52 0.32 0.03 0.01 0.01 0.17 < 0.01 < 0.01 0.05 1.53

7 91.99 5.11 0.36 0.05 0.01 0.01 0.02 < 0.01 < 0.01 0.05 1.80

8 93.14 4.81 0.14 0.03 0.01 0.01 0.02 < 0.01 < 0.01 0.01 1.72

9 94.02 4.15 0.10 0.03 0.01 0.01 0.02 < 0.01 < 0.01 0.01 1.51

10 95.11 3.42 0.13 0.03 0.01 0.01 0.01 < 0.01 < 0.01 0.01 1.51

11 93.45 4.45 0.19 0.04 0.03 0.01 0.08 < 0.01 < 0.01 0.06 1.55

12 90.32 6.54 0.35 0.04 0.01 0.01 0.13 < 0.01 < 0.01 0.06 2.13

13 89.12 8.68 0.20 0.01 0.01 0.01 0.22 0.01 0.01 0.04 2.71

Min. 89.12 3.42 0.10 0.01 0.01 0.01 0.01 < 0.01 < 0.01 0.01 1.43

Max. 95.11 8.68 0.36 0.09 0.03 0.01 0.22 0.01 0.01 0.07 2.71

Aver. 92.24 5.31 0.23 0.04 0.02 0.01 0.11 0.00 0.00 0.04 1.83

Overall average 92.77 5.03 0.20 0.04 0.01 0.01 0.09 0.00 0.00 0.04 1.63

Fig. 5: Histograms showing the distribution of the various grain sizes (average) in the original sand samples.

Table 2: Characteristics of the separated sand fractions.

Grain- size Description

2 -1 mm White, rounded to well- rounded quartz grains, predominantly monocrystalline.

1 – 0.5 mm White, rounded to subrounded quartz grains, mainly monocrystalline.

0.5 – 0.25 mm White, subrounded to subangular grains and brownish yellow cloudy polycrystalline grains.

0.25 – 0.125 mm White and brownish white, Subrounded to subangular quartz grains.

0.125 – 0.063 mm White, subangular to angular quartz grains, with traces of heavy minerals.

< 0.063 mm Brownish green, angular quartz grains, occasionally coated by iron oxides with heavy minerals.


Plate 1: (A) Photomicrograph of the quartz- rich Naqus sandstone. The rock consists of monocrystalline, fine -

to - medium, moderately- to- well sorted subrounded, quartz grains with low content of impurities (Sec.

B, S. No.6); (B) SEM photomicrograph showing medium to- coarse, rounded to subangular quartz

grains (Sec. A, S. No.8). (C and D) SEM photomicrograph of sandstones composed essentially of

quartz, medium- to fine- grained, moderately- to well- sorted, and moderately- cemented. Minor of

detrital clays occur mainly as grain rimming and /or coatings (Sec.A, S. No.14 and Sec. B, S. No.1).

4- Surface textural analysis of quartz grains by scanning electron microscopy (SEM):

SEM examination revealed that the original samples are composed essentially of quartz, fine-to- medium

grained, moderately- to well- sorted quartz grains. They are rarely to moderately- cemented and, thus, display

open packing. Detrital clays occur mainly as quartz grain coatings around grains (Plate 1: C and D).

SEM examinations of the studied sands showed that the grain surface textures characteristic of mechanical

weathering features are rather common whereas those indicative of chemical weathering rare. These include

conchoidal fractures (Plate 2: A and B), straight grooves, (Plate 2: C and D) and crescentic gouges (Plate 2: E

and F). These features association suggests deposition in moderate– to– high- energy aqueous environments (cf.

Krinsley and Doornkamp, 1973 and Madhavarajuet et al., 2009).

5- Heavy mineral analysis of sand samples:

Generally, heavy minerals form a minor constituent of the studied sandstone samples (trace to <0.5%).

They are more enriched in the very fine sand fractions than in the fine sand fractions. The assemblage is

characterized by low diversity, being consisted mainly of rounded to well- rounded grains of zircon (3- 9%),

tourmaline (2- 5%) and rutile (1- 2%).This suggests derivation either from igneous or metamorphic rocks (Blatt

and Murray, 1980 and Morton et al., 1992).


Plate 2: SEM photomicrographs showing the microtextures displayed by the quartz grains of the Naqus

sandstones, (A and B) Conchoidal fractures on subangular, elongated, flatted and subrounded quartz

grains(Sec.A, S. No. 3 and Sec. B, S. No. 2); (C and D) Straight grooves on subangular quartz

grains (Sec.A, S. No. 8 and Sec. B, S. No. 7); (E and F) Crescentic gouges on subangular and

subrounded quartz grains(Sec.A, S. No. 18 and Sec. B, S. No. 11).

B- Economic potential:

1- The chemical analyses emphasized that the concentrations of Cr in the studied samples range between

(1 to 2 ppm.),which meets the requirements for glass production given by the British standard specifications,

(Table 3), while the major element proportions of these samples revealed that the studied sands must be

subjected to beneficiation processes to increase the SiO2 content of the raw sands and to reduce iron and

titanium compounds, their contents of contaminants (clay, organic matter and heavy minerals) to achieve the

desired “cleaned particles” and improve their quality in order to meet the specifications required for the

production of glass.

2- More than 88 to 90% of the grains representing section (A) and section (B); respectively fall mainly in

the range of 1.0 to 0.125 mm (coarse, medium and fine sands) which is suitable for all kinds of glass production

according to the standard American and British specifications (Table 6). The fractions constitute the very coarse


sand and the fractions < 0.125 mm which contain mostly kaolin (clay mineral) are not suitable for glass making

and must be separated.

3- The surface textures of the quartz grain surfaces display mainly mechanical weathering features

whereas those indicative of chemical weathering are not recorded. This makes the studied sands suitable for the

manufacture of all kinds of glass based on the standard American and British specifications.

4- The heavy minerals considered as (impurities), are not suitable for glass making and must be separated.

Table (3) shows the British standard specifications (BS 2975, 1988) for the classification of quality grade of

glass sand based on the chemical composition, Table (4) shows the British standard (BS 2975, 1988) depending

on usage and Table (5) shows American standard specifications (Norton, 1957) for glass sand depending on

usage. Table (6) shows the standard specifications of the American and British for grain- size grading for these

sands.

Table 3: The British Standards (BS 2975, 1988) for the classification of glass sand based on chemical composition.

Chemical composition% Quality Grade

1 2 3 4 5

SiO2 99.74 99.55 98.23 97.4 95.1

Al2O3 0.061 0.068 0.65 1.03 2.03

Fe2O3 0.014 0.033 0.064 0.095 0.273

TiO2 0.026 0.064 0.033 0.033 0.087

MnO 0.02 0.02 0.02 0.02 0.05

CaO 0.02 0.02 0.02 0.04 0.13

Na2O 0.02 0.02 0.02 0.07 0.02

K2O 0.02 0.02 0.42 0.63 1.22

Cr2O3 0.0003 0.0011 0.0004 0.0005 0.0017

L.O.I at 900ºC 0.12 0.14 0.2 0.27 0.47

Table 4: The British Standards (BS 2975, 1988) for the classification of glass sand for various usage aspects.

Uses Chemical composition %

SiO2 Al2O3 Fe2O3 Cr2O3 Cu Co Ni V Na2O +

K2O

L.O.I

Glass lenses >99.7 <0.2 <0.012 0.0001 0.000

1

0.01 0.0001 0.0003 - 0.2

Crystals industry 99.6±0.1 0.2±0.1 0.01 0.0002 ,, ,, ,, ,, - 0.1

Thermal glass 99.6±0.1 0.2±0.1 0.003±0.03 0.0005 ,, ,, ,, ,, - 0.1

Transparent glass 98.8±0.2 0.2±0.1 0.10

±0.0005 0.0005 ,, ,, ,, ,, - 0.2

Ordinary glass

panels

99.0 ±0.2 0.5±0.15 0.25±0.03 0.0005 ,, ,, ,, ,, - 0.2

Colored glass 97.0 ±0.3 0.5±0.1 0.30 ±0.05 0.0005 ,, ,, ,, ,, - 0.5

Reinforced glass 94.5±0.5 0.3± 0.05 0.30 ±0.05 0.0005 ,, ,, ,, ,, 2.5± 0.3 0.5

Table 5: The American Standards (Norton, 1957) for the classification of glass sand for various usage aspects.

Quality Grade Uses Chemical composition %

SiO2(Min.) Al2O3(Max.) Fe2O3(Max.) CaO + MgO(Max.)

1 Optical glass 99.8 0.1 0.020 0.10

2 Flint glass container 98.5 0.5 0.035 0.20

3 Flint glass 95.0 4.0 0.035 0.50

4 Sheet and plate glass 98.5 0.5 0.060 0.50

5 Sheet and plate glass 95.0 4.0 0.060 0.50

6 Colored glass containers 98.0 0.5 0.300 0.50

7 Colored glass 95.0 4.0 0.300 0.50

8 Ground glass container 98.0 0.5 1.000 0.50

9 Ground glass 95.0 4.0 1.000 0.50

Table 6: Specifications of the grain- size grading as given by the American and British Standards.

Size (microns) Percentage of allowable weight (%)

+1000 0

600 - 1000 2to 6

420 - 600 10 to 15

150 - 420 Minimum80

125 - 150 Maximum 10

-125 Maximum 5

After a previous chemical investigations on the studied raw sand samples (Sec., A and Sec., B) by Abou El-

Anwar and El-Wekeil (2013), the laboratory beneficiation studies were initiated after the completion of

characterization studies on the representative raw sand samples by the present authors.


Result and Discussion after beneficiation processes:

1- Chemical analysis of attrited samples:

The results of the chemical analysis (Table 7) for the attrited white samplesrevealed that the proportions of

SiO2 range mainly from 95.23 to 99.17%(average, 98.59%); Fe2O3<0.01 to 0.06%(average, 0.025%); TiO2 0.03

to 0.12 %(average, 0.072%).This meet the specifications required for industrial glass sands.

Table 7: Chemical composition (%)of the white sands after the attrition scrubbing process.

Section S.No. SiO2 Al2O3 TiO2 Fe2O3 MgO MnO CaO Na2O K2O P2O5 L.O.I

Sec

tion

A

1 98.32 0.95 0.06 0.02 0.01 0.01 0.11 0.01 0.01 0.02 0.23

2 95.23 3.65 0.05 0.02 0.01 0.01 0.17 0.01 0.01 0.01 0.59

3 98.45 0.94 0.05 0.01 0.01 0.01 0.08 0.01 0.01 0.01 0.19

4 98.45 0.66 0.09 0.03 0.01 0.01 0.06 0.01 0.01 0.01 0.42

5 98.45 0.34 0.07 < 0.01 < 0.01 < 0.01 0.12 < 0.01 < 0.01 0.01 0.37

6 98.85 0.25 0.06 < 0.01 < 0.01 < 0.01 0.23 < 0.01 < 0.01 0.03 0.11

7 99.17 0.24 0.05 < 0.01 < 0.01 < 0.01 0.08 < 0.01 < 0.01 0.01 0.27

8 99.10 0.34 0.08 < 0.01 < 0.01 < 0.01 0.08 < 0.01 < 0.01 0.02 0.47

9 98.56 0.32 0.11 < 0.01 < 0.01 < 0.01 0.09 < 0.01 < 0.01 0.01 0.32

10 98.85 0.23 0.06 < 0.01 < 0.01 < 0.01 0.07 < 0.01 < 0.01 0.01 0.23

11 99.12 0.24 0.05 < 0.01 < 0.01 < 0.01 0.09 < 0.01 < 0.01 0.01 0.49

12 98.92 0.34 0.07 < 0.01 < 0.01 < 0.01 0.08 < 0.01 < 0.01 0.01 0.33

13 99.06 0.34 0.05 0.01 < 0.01 < 0.01 0.09 < 0.01 < 0.01 0.01 0.22

14 98.64 0.31 0.06 < 0.01 < 0.01 < 0.01 0.06 < 0.01 < 0.01 0.01 0.28

15 99.01 0.19 0.11 0.05 < 0.01 < 0.01 0.07 < 0.01 < 0.01 0.01 0.61

16 97.99 0.68 0.09 0.04 < 0.01 < 0.01 0.07 < 0.01 < 0.01 0.01 0.22

17 98.89 0.38 0.08 0.04 < 0.01 < 0.01 0.11 < 0.01 < 0.01 0.01 0.56

18 98.45 0.66 0.08 0.04 < 0.01 < 0.01 0.08 < 0.01 < 0.01 0.01 0.50

Min. 95.23 0.19 0.05 < 0.01 < 0.01 < 0.01 0.06 < 0.01 < 0.01 0.01 0.11

Max. 99.17 3.65 0.11 0.05 0.01 0.01 0.23 0.01 0.01 0.03 0.61

Aver. 98.53 0.61 0.07 0.01 0.00 0.00 0.10 0.00 0.00 0.01 0.36

Sec

tion

B

1 98.78 0.73 0.06 0.06 < 0.01 < 0.01 0.12 < 0.01 < 0.01 0.01 0.40

2 98.57 0.57 0.08 0.05 < 0.01 < 0.01 0.13 < 0.01 < 0.01 0.01 0.34

3 98.87 0.43 0.03 0.04 < 0.01 < 0.01 0.10 < 0.01 < 0.01 0.02 0.32

4 98.47 0.18 0.11 0.04 < 0.01 < 0.01 0.17 < 0.01 < 0.01 0.02 0.40

5 98.45 0.42 0.12 0.03 < 0.01 < 0.01 0.13 < 0.01 < 0.01 0.06 0.50

6 98.34 0.55 0.12 0.02 < 0.01 < 0.01 0.12 < 0.01 < 0.01 0.02 0.62

7 99.01 0.10 0.05 0.04 < 0.01 < 0.01 0.06 < 0.01 < 0.01 0.01 0.41

8 98.84 0.46 0.05 0.03 < 0.01 < 0.01 0.03 < 0.01 < 0.01 0.01 0.22

9 98.22 0.85 0.07 0.04 < 0.01 < 0.01 0.02 < 0.01 < 0.01 0.01 0.43

10 98.88 0.77 0.10 0.03 < 0.01 < 0.01 0.02 < 0.01 < 0.01 0.01 0.26

11 99.12 0.41 0.06 0.06 < 0.01 < 0.01 0.08 < 0.01 < 0.01 0.01 0.27

12 98.75 0.10 0.06 0.03 < 0.01 < 0.01 0.07 < 0.01 < 0.01 0.01 0.40

13 98.42 0.86 0.04 0.03 < 0.01 < 0.01 0.08 < 0.01 < 0.01 0.01 0.21

Min. 98.22 0.10 0.03 0.02 < 0.01 < 0.01 0.02 < 0.01 < 0.01 0.01 0.21

Max. 99.12 0.86 0.12 0.06 < 0.01 < 0.01 0.17 < 0.01 < 0.01 0.06 0.62

Aver. 98.67 0.49 0.07 0.04 0.00 0.00 0.09 0.00 0.00 0.02 0.37

Overall average 98.60 0.55 0.07 0.03 0.00 0.00 0.09 0.00 0.00 0.01 0.36

2- Textural Grain- sized characteristics:

The results of grain- size analyses showed generation of fines in attrited sand as a result of their abrasion.

Coarser particles were subjected to deagglomeration and to a much lesser extent, grinding (minimum of size

reduction of quartz grains due to the attrition process). This is evident when comparing between Fig (5) and Fig

(6) which show sand before and after attrition.

The particle- size distributions of the attrited samples reveal that more than 89.94 (section A) to 92.16 %

(section B) of grains of the glass silica sands fall mainly in the 1.0 to 0.125 mm size grades (coarse, medium and

fine sands).This size composition is suitable for the productionof all kinds of glass according to specifications of

the American and British standards.

3- Chemical composition of the attrited white sands after hydrocyclone process:

Conducting the hydrocyclone operation on the attrited white sands generated afinal product made up of

sand, mixture of sand and kaolin, kaolin Ι and kaolin Π. The weight percentages of these products (Table

8)range from 87.07 to 92.09%,from 2.10 to 7.24%, from 2.02 to 6.49% and from 1.06 to 2.69% respectively.


The weight percentages of white kaolin (mixtures of sand and kaolin, kaolin Ι and kaolin Π)lie in the range 8-

13% (average, 11%).

Fig. 6: Histograms showing the grain size (average) distribution in the samples subjected to attrition scrubbing.

The chemical analyses data of kaolin Ι, kaolin Π and mixtures of sand and kaolin(white kaolin) are given in

Tables(9), (10), and (11). SiO2 contents of these fractions average 46.60, 47.75and 59.09%; respectively. Their

Al2O3contentsaverage 37.07, 36.75 and29.56%; respectively. A comparison between the averages chemical

compositions of the main components in the end product of the studied attrited samples after hydrocyclone

process is shown in Table (12).

The grain- size composition of the original samples(63-125 μm) range from 4.77 to 19.50% and changed to

1.33 to 20.29% after attrition (Figs, 4 and 5).

The results of chemical and grain-size analyses revealed that kaolinΙ can be used in ceramic and paper

industries (filling and coating of paper)according to Indian Standard Specifications (1965).

Table 8: Sand-clay composition (wt %) of the attrited white sands subjected tohydrocyclone process.

Section S.No. Sand Sand+

Kaolin

Kaolin

I

Kaolin

II

Section S.No. Sand Sand+

Kaolin

Kaolin

I

Kaolin

II

Sec

tion

A

1 89.09 5.11 4.69 1.11

Sec

tion

B

1 89.80 5.91 2.35 1.94

2 88.41 5.50 5.03 1.06 2 90.06 6.15 2.19 1.60

3 89.14 4.33 5.14 1.39 3 90.78 5.41 2.16 1.65

4 87.07 7.24 3.22 2.47 4 88.91 6.84 2.38 1.87

5 88.66 3.97 5.18 2.19 5 90.11 5.52 2.74 1.63

6 89.85 3.17 4.77 2.21 6 90.52 5.17 2.54 1.77

7 91.99 2.10 4.06 1.85 7 88.40 7.00 2.48 2.12

8 89.30 3.48 4.99 2.23 8 89.10 4.02 4.70 2.18

9 90.21 2.73 5.03 2.03 9 90.28 4.34 3.45 1.93

10 90.67 2.36 4.81 2.16 10 90.41 2.12 4.96 2.51

11 89.19 3.33 5.27 2.21 11 89.48 5.90 2.83 1.79

12 89.38 2.86 5.53 2.23 12 89.30 6.10 2.87 1.73

13 87.88 3.76 5.71 2.65 13 87.43 4.70 6.49 1.38

14 88.03 4.38 4.90 2.69 Min. 87.43 2.12 2.16 1.38

15 90.36 5.61 2.40 1.63 Max. 90.78 7.00 6.49 2.51

16 92.09 4.44 2.12 1.35 Aver. 89.58 5.32 3.24 1.85

17 90.00 6.06 2.17 1.77 Overall average 89.59 4.76 3.76 1.89

18 91.42 5.08 2.02 1.48

Min. 87.07 2.10 2.02 1.06

Max. 92.09 7.24 5.71 2.69

Aver. 89.60 4.20 4.28 1.93

Table 9: Chemical composition (%) of kaolin I after treatment with the hydrocyclone process.

Section S.No. SiO2 Al2O3 TiO2 Fe2O3 MgO MnO CaO Na2O K2O P2O5 L.O.I.

Sec

tion

A

1 48.23 35.81 1.10 0.33 0.13 0.01 0.40 0.01 0.01 0.03 13.60

2 48.11 35.12 1.62 0.44 0.13 0.01 0.30 0.01 0.01 0.15 13.92

3 47.56 36.11 1.28 0.40 0.15 0.01 0.40 0.01 0.01 0.17 13.48

4 45.87 38.42 1.01 0.44 0.01 0.01 0.11 0.01 0.01 0.18 14.58

5 46.00 36.71 1.14 0.53 0.23 0.01 0.37 0.01 0.01 0.18 14.25

6 46.08 37.14 1.12 0.42 0.21 0.01 0.39 0.01 0.01 0.17 14.34

7 46.02 36.96 0.88 0.69 0.23 0.01 0.54 0.01 0.01 0.12 13.81

8 46.85 36.70 1.33 0.41 0.19 0.01 0.36 0.01 0.01 0.15 14.68

9 46.41 36.04 1.47 0.47 0.18 0.01 0.33 0.01 0.01 0.21 14.97

10 46.62 35.67 1.04 0.41 0.19 0.01 0.78 0.01 0.01 0.14 13.98


11 47.31 36.28 1.04 0.44 0.16 0.01 0.43 0.01 0.01 0.14 14.50

12 47.67 36.32 1.32 0.44 0.11 0.01 0.35 0.01 0.01 0.11 14.53

13 46.74 35.88 1.45 0.44 0.18 0.01 0.73 0.01 0.01 0.19 14.66

14 46.41 35.79 1.75 0.46 0.21 0.01 0.31 0.01 0.01 0.20 13.95

15 45.44 38.71 0.73 0.37 0.01 0.01 0.18 0.01 0.01 0.20 13.85

16 45.84 38.19 0.73 0.38 0.07 0.01 0.32 0.01 0.01 0.22 13.64

17 45.70 38.72 0.77 0.36 0.01 0.01 0.16 0.01 0.01 0.21 13.56

18 46.26 38.56 0.77 0.38 0.01 0.01 0.16 0.01 0.01 0.20 13.75

Min. 45.44 35.12 0.73 0.33 0.01 0.01 0.11 0.01 0.01 0.03 13.48

Max. 48.23 38.72 1.75 0.69 0.23 0.01 0.78 0.01 0.01 0.22 14.97

Aver. 46.62 36.84 1.14 0.43 0.13 0.01 0.37 0.01 0.01 0.17 14.11

Sec

tion

B

1 46.24 38.52 0.69 0.34 0.01 0.01 0.01 0.18 0.01 0.16 13.75

2 45.93 38.44 0.85 0.46 0.01 0.01 0.01 0.16 0.01 0.20 13.01

3 46.65 37.67 0.86 0.38 0.01 0.01 0.01 0.17 0.01 0.22 13.65

4 45.68 36.99 1.20 0.55 0.01 0.01 0.01 0.29 0.01 0.29 13.96

5 46.21 37.41 1.05 0.45 0.01 0.01 0.01 0.19 0.01 0.27 13.85

6 46.32 37.22 1.11 0.45 0.01 0.01 0.01 0.20 0.01 0.20 13.97

7 45.87 37.47 1.41 0.49 0.01 0.01 0.01 0.13 0.01 0.24 13.98

8 46.10 38.22 0.77 0.39 0.01 0.01 0.01 0.13 0.01 0.17 13.85

9 46.17 38.25 0.49 0.35 0.01 0.01 0.01 0.16 0.01 0.11 13.92

10 46.45 37.25 0.94 0.49 0.01 0.01 0.01 0.31 0.01 0.16 13.78

11 46.32 38.19 0.85 0.39 0.01 0.01 0.01 0.19 0.01 0.21 13.96

12 46.40 37.16 0.66 0.47 0.01 0.01 0.01 0.22 0.01 0.28 14.16

13 51.11 33.23 0.34 0.43 0.01 0.01 0.01 0.38 0.01 0.13 13.69

Min. 45.68 33.23 0.34 0.34 0.01 0.01 0.01 0.13 0.01 0.11 13.01

Max. 51.11 38.52 1.41 0.55 0.01 0.01 0.01 0.38 0.01 0.29 14.16

Aver. 46.57 37.39 0.86 0.43 0.01 0.01 0.01 0.21 0.01 0.20 13.81

Overall average 46.60 37.11 1.00 0.43 0.07 0.01 0.19 0.11 0.01 0.18 13.96

Table 10: Chemical composition (%) of kaolin II after treatment with the hydrocyclone process.

Section S.No. SiO2 Al2O3 TiO2 Fe2O3 MgO MnO CaO Na2O K2O P2O5 L.O.I.

Sec

tion

A

1 48.23 36.27 0.81 0.25 0.13 0.10 0.41 0.10 0.10 0.10 13.48

2 48.00 36.01 1.16 0.34 0.14 0.10 0.38 0.10 0.10 0.12 13.65

3 50.32 34.40 1.07 0.32 0.10 0.10 0.16 0.10 0.10 0.12 12.91

4 46.83 38.15 0.77 0.38 0.10 0.10 0.38 0.10 0.10 0.15 13.53

5 48.09 36.42 0.69 0.41 0.16 0.10 0.19 0.10 0.10 0.10 13.27

6 48.64 36.92 0.92 0.32 0.13 0.10 0.17 0.10 0.10 0.12 13.28

7 48.49 35.99 0.63 0.48 0.15 0.10 0.21 0.10 0.10 0.09 13.47

8 48.06 36.32 1.04 0.33 0.15 0.10 0.24 0.10 0.10 0.13 13.38

9 48.26 36.39 1.19 0.38 0.15 0.10 0.21 0.10 0.10 0.13 13.29

10 46.99 36.36 0.88 0.34 0.17 0.10 0.31 0.10 0.10 0.11 14.17

11 43.26 36.04 0.82 0.35 0.14 0.10 0.18 0.10 0.10 0.09 13.72

12 50.56 34.90 1.21 0.34 0.08 0.10 0.39 0.10 0.10 0.13 12.18

13 48.05 35.67 1.16 0.36 0.13 0.10 0.30 0.10 0.10 0.13 13.89

14 48.12 35.17 1.60 0.39 0.17 0.10 0.44 0.10 0.10 0.15 13.88

15 46.94 38.25 0.59 0.35 0.10 0.10 0.10 0.10 0.10 0.16 13.46

16 46.69 37.79 0.60 0.32 0.10 0.10 0.35 0.10 0.10 0.18 13.81

17 46.59 38.33 0.56 0.31 0.10 0.10 0.37 0.10 0.10 0.15 13.67

18 47.59 37.85 0.56 0.29 0.10 0.10 0.51 0.10 0.10 0.16 13.26

Min. 43.26 34.40 0.56 0.25 0.08 0.10 0.10 0.10 0.10 0.09 12.18

Max. 50.56 38.33 1.60 0.48 0.17 0.10 0.51 0.10 0.10 0.18 14.17

Aver. 47.76 36.51 0.90 0.35 0.13 0.10 0.29 0.10 0.10 0.13 13.46

Sec

tion

B

1 47.23 38.00 0.52 0.32 0.10 0.10 0.40 0.10 0.10 0.13 13.48

2 47.31 37.24 0.73 0.35 0.10 0.10 0.32 0.10 0.10 0.17 13.86

3 47.29 37.15 0.76 0.36 0.10 0.10 0.77 0.10 0.10 0.21 13.25

4 47.24 36.87 0.87 0.44 0.10 0.10 0.39 0.10 0.10 0.17 13.58

5 47.54 37.55 0.78 0.37 0.10 0.10 0.42 0.10 0.10 0.16 13.35

6 47.31 37.70 0.81 0.35 0.10 0.10 0.22 0.10 0.10 0.14 13.34

7 48.04 37.06 1.01 0.40 0.10 0.10 0.15 0.10 0.10 0.15 13.09

8 47.75 37.45 0.64 0.31 0.10 0.10 0.15 0.10 0.10 0.11 13.42

9 46.87 37.16 0.83 0.54 0.10 0.10 0.18 0.10 0.10 0.13 13.85

10 47.67 36.71 0.89 0.45 0.10 0.10 0.34 0.10 0.10 0.13 13.48

11 47.51 37.95 0.60 0.32 0.10 0.10 0.18 0.10 0.10 0.15 13.18

12 47.51 37.22 0.97 0.38 0.10 0.10 0.23 0.10 0.10 0.17 13.46

13 51.22 34.00 0.98 0.29 0.10 0.10 0.53 0.10 0.10 0.10 12.44

Min. 46.87 34.00 0.52 0.29 0.10 0.10 0.15 0.10 0.10 0.10 12.44

Max. 51.22 38.00 1.01 0.54 0.10 0.10 0.77 0.10 0.10 0.21 13.86

Aver. 47.73 37.08 0.80 0.38 0.10 0.10 0.33 0.10 0.10 0.15 13.37

Overall average 47.75 36.80 0.85 0.36 0.11 0.10 0.31 0.10 0.10 0.14 13.41


Table 11: Chemical composition (%)of mixed sand and kaolin after treatment with the hydrocyclone process.

Section S.No. SiO2 Al2O3 TiO2 Fe2O3 MgO MnO CaO Na2O K2O P2O5 L.O.I. S

ecti

on

A

1 59.12 31.23 1.04 0.15 0.90 0.01 0.53 0.01 0.01 0.06 7.57

2 57.75 31.23 1.53 0.21 0.09 0.01 0.53 0.01 0.01 0.08 8.33

3 58.35 31.18 1.25 0.20 0.11 0.01 0.40 0.01 0.01 0.07 8.04

4 61.56 27.23 0.69 0.20 0.01 0.01 0.12 0.01 0.01 0.05 9.54

5 63.23 27.03 1.29 0.20 0.05 0.01 0.55 0.01 0.01 0.02 7.26

6 60.36 28.57 1.43 0.20 0.04 0.01 0.50 0.01 0.01 0.03 8.73

7 64.80 27.70 0.86 0.33 0.05 0.01 0.90 0.01 0.01 0.04 5.19

8 57.81 30.07 1.24 0.22 0.06 0.01 0.67 0.01 0.01 0.05 9.74

9 58.85 29.46 1.11 0.25 0.05 0.01 0.49 0.01 0.01 0.03 9.52

10 60.25 27.98 1.05 0.21 0.07 0.01 1.05 0.01 0.01 0.04 9.00

11 61.75 27.97 1.82 0.25 0.03 0.01 0.55 0.01 0.01 0.03 8.21

12 67.80 22.56 1.58 0.18 0.06 0.01 0.56 0.01 0.01 0.05 6.92

13 58.27 29.78 2.36 0.29 0.01 0.01 0.80 0.01 0.01 0.04 9.03

14 62.65 26.56 0.52 0.20 0.01 0.01 0.58 0.01 0.01 0.03 8.47

15 56.85 31.23 0.68 0.26 0.01 0.01 0.21 0.01 0.01 0.05 10.65

16 54.44 32.57 0.56 0.28 0.01 0.01 0.44 0.01 0.01 0.05 11.40

17 54.43 33.45 0.44 0.29 0.01 0.01 0.28 0.01 0.01 0.04 10.87

18 56.56 31.12 0.45 0.22 0.01 0.01 0.22 0.01 0.01 0.05 10.59

Min. 54.43 22.56 0.44 0.15 0.01 0.01 0.12 0.01 0.01 0.02 5.19

Max. 67.80 33.45 2.36 0.33 0.90 0.01 1.05 0.01 0.01 0.08 11.40

Aver. 59.71 29.27 1.11 0.23 0.09 0.01 0.52 0.01 0.01 0.05 8.84

Sec

tion

B

1 54.76 33.12 0.80 0.24 0.01 0.01 0.32 0.01 0.01 0.04 10.75

2 55.93 31.98 0.52 0.29 0.01 0.01 0.49 0.01 0.01 0.06 10.43

3 52.19 34.15 0.57 0.25 0.01 0.01 0.22 0.01 0.01 0.06 12.15

4 69.87 21.11 0.89 0.22 0.01 0.01 0.19 0.01 0.01 0.04 7.41

5 57.89 29.54 0.57 0.31 0.01 0.01 0.32 0.01 0.01 0.06 10.30

6 52.65 33.35 0.85 0.30 0.01 0.01 0.36 0.01 0.01 0.05 11.90

7 59.89 28.24 0.83 0.31 0.01 0.01 0.19 0.01 0.01 0.04 9.89

8 62.28 26.98 0.97 0.23 0.01 0.01 0.30 0.01 0.01 0.04 8.82

9 55.93 31.66 0.51 0.29 0.01 0.01 0.30 0.01 0.01 0.05 10.87

10 62.71 26.93 1.03 0.24 0.01 0.01 0.45 0.01 0.01 0.05 8.84

11 56.86 32.12 0.55 0.24 0.01 0.01 0.26 0.01 0.01 0.04 9.38

12 59.11 29.05 0.90 0.31 0.01 0.01 0.30 0.01 0.01 0.06 10.29

13 56.86 31.33 1.05 0.26 0.01 0.01 0.54 0.01 0.01 0.07 9.11

Min. 52.19 21.11 0.51 0.22 0.01 0.01 0.19 0.01 0.01 0.04 7.41

Max. 69.87 34.15 1.05 0.31 0.01 0.01 0.54 0.01 0.01 0.07 12.15

Aver. 58.23 29.97 0.77 0.27 0.01 0.01 0.33 0.01 0.01 0.05 10.01

Overall average 59.09 58.97 29.62 0.94 0.25 0.05 0.01 0.42 0.01 0.01 0.05

Table 12: Comparison between the chemical compositions(averages %) of the end products of the studied sand samples after treatment with the hydrocyclone process.

Oxides SiO2 Al2O3 TiO2 Fe2O3 MgO MnO CaO Na2O K2O P2O5 L.O.I.

Kaolin I 46.60 37.07 1.02 0.43 0.08 0.01 0.22 0.09 0.01 0.18 13.99

Kaolin II 47.75 36.75 0.86 0.36 0.12 0.10 0.31 0.10 0.10 0.14 13.42

Mixed Sand & Kaolin 59.09 29.56 0.97 0.25 0.06 0.01 0.44 0.01 0.01 0.05 9.33

Low and High Intensity electromagnetic Separation:

a) The end products of sand after hydrocyclone process were subjected to dry low and high

electromagnetic separation. The chemical composition of the products(Table 13) show that SiO2 ranges from

97.54 to 99.27% (average98.75%), Fe2O3from< 0.01 to 0.05 % (average 0.019%) and TiO2 from 0.03 to 0.08%

(average 0.045%).A comparison between the averages of chemical compositions of the main components in the

studied sand samples before and after beneficiation processes is shown in Table (14).It reveals that the

beneficiated sand complies with 2nd

- 9th

grades of the American Standard specifications while complies with 3rd

-

5th

grades assigned by the British Standard specification.

According to Iron Oxide Standards given by the Ceramic Industry Magazine (1966), the final product of

silica sand is suitable for manufacturing of all kinds of glass except for the optical glass(Table 15).

b- Dry magnetic separation was conducted on the size 50- 100 μm produced after hydrocyclone process in

order to separate the magnetic (impurities) and nonmagnetic minerals to obtain higher quality products of white

kaolin suitable for manufacture ceramic. The weight percentages of these sizes were calculated and their

averages were presented graphically in the form of histograms (Fig. 7).


Table 13: Chemical composition (%)of the white sands subjected to magnetic separation.

Section S.No. SiO2 Al2O3 TiO2 Fe2O3 MgO MnO CaO Na2O K2O P2O5 L.O.I S

ecti

on

A

1 98.23 0.98 0.03 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.27

2 98.45 0.88 0.06 0.02 0.01 0.01 0.14 0.01 0.01 0.01 0.10

3 98.45 0.94 0.03 0.02 0.01 0.01 0.07 0.01 0.01 0.01 0.18

4 98.99 0.33 0.05 0.03 0.01 0.01 0.05 0.01 0.01 0.01 0.31

5 98.76 0.28 0.04 < 0.01 < 0.01 < 0.01 0.06 < 0.01 < 0.01 < 0.01 0.37

6 99.23 0.24 0.04 < 0.01 < 0.01 < 0.01 0.15 < 0.01 < 0.01 < 0.01 0.18

7 99.24 0.21 0.03 < 0.01 < 0.01 < 0.01 0.07 < 0.01 < 0.01 < 0.01 0.21

8 99.15 0.33 0.06 < 0.01 < 0.01 < 0.01 0.04 < 0.01 < 0.01 < 0.01 0.40

9 99.20 0.32 0.05 < 0.01 < 0.01 < 0.01 0.07 < 0.01 < 0.01 < 0.01 0.15

10 99.27 0.23 0.04 < 0.01 < 0.01 < 0.01 0.06 < 0.01 < 0.01 < 0.01 0.13

11 99.13 0.23 0.04 < 0.01 < 0.01 < 0.01 0.05 < 0.01 < 0.01 < 0.01 0.26

12 98.83 0.31 0.05 < 0.01 < 0.01 < 0.01 0.06 < 0.01 < 0.01 < 0.01 0.29

13 98.89 0.34 0.06 0.01 0.01 0.01 0.06 0.01 0.01 0.01 0.23

14 98.75 0.38 0.08 < 0.01 0.01 0.01 0.05 0.01 0.01 0.01 0.35

15 99.10 0.22 0.03 0.04 0.01 0.01 0.05 0.01 0.01 0.01 0.17

16 98.46 0.66 0.04 0.03 0.01 0.01 0.08 0.01 0.01 0.01 0.26

17 98.35 0.42 0.04 0.03 0.01 0.01 0.09 0.01 0.01 0.01 0.34

18 98.60 0.63 0.03 0.03 0.01 0.01 0.08 0.01 0.01 0.01 0.38

Min. 98.23 0.21 0.03 < 0.01 < 0.01 < 0.01 0.01 < 0.01 < 0.01 < 0.01 0.10

Max. 99.27 0.66 0.08 0.04 0.01 0.01 0.15 0.01 0.01 0.01 0.40

Aver. 98.84 0.44 0.04 0.01 0.01 0.01 0.07 0.01 0.01 0.01 0.25

Sec

tion

B

1 98.65 0.82 0.04 0.04 0.01 0.01 0.11 0.01 0.01 0.01 0.53

2 98.38 0.68 0.06 0.04 0.01 0.01 0.11 0.01 0.01 0.01 0.39

3 99.00 0.43 0.04 0.03 0.01 0.01 0.11 0.01 0.01 0.01 0.33

4 98.99 0.15 0.08 0.03 0.01 0.01 0.07 0.01 0.01 0.02 0.43

5 98.87 0.45 0.05 0.02 0.01 0.01 0.10 0.01 0.01 0.01 0.17

6 98.87 0.53 0.06 0.02 0.01 0.01 0.11 0.01 0.01 0.02 0.33

7 99.11 0.11 0.05 0.03 0.01 0.01 0.07 0.01 0.01 0.02 0.40

8 99.11 0.49 0.03 0.02 0.01 0.01 0.02 0.01 0.01 0.01 0.16

9 98.63 0.75 0.03 0.03 0.01 0.01 0.01 0.01 0.01 0.01 0.27

10 98.65 0.73 0.05 0.02 0.01 0.01 0.02 0.01 0.01 0.01 0.29

11 98.94 0.32 0.06 0.05 0.01 0.01 0.08 0.01 0.01 0.01 0.28

12 99.02 0.13 0.03 0.02 0.01 0.01 0.09 0.01 0.01 0.01 0.34

13 98.56 0.95 0.03 0.02 0.01 0.01 0.07 0.01 0.01 0.01 0.07

Min. 98.38 0.11 0.03 0.02 0.01 0.01 0.01 0.01 0.01 0.01 0.07

Max. 99.11 0.95 0.08 0.04 0.01 0.01 0.11 0.01 0.01 0.02 0.53

Aver. 98.83 0.50 0.05 0.03 0.01 0.01 0.07 0.01 0.01 0.01 0.31

Overall average 98.83 0.47 0.05 0.02 0.01 0.01 0.07 0.01 0.01 0.01 0.28

Table 14: Comparison between the averages of chemical compositions (%) of the main components in the studied sand samples before and

after beneficiation processes with respect to the American and British Standard specifications.

Method

SiO2% Al2O3% Fe2O3% (CaO + MgO) % TiO2%

Before After Before After Before After Before After Before After

Attrition scrubbing 92.85 98.59 4.98 0.56 0.04 0.025 0.15 0.091 0.19 0.072

Magnetic 98.83 0.47 0.019 0.078 0.045

American Standard

2nd grade Min. 98.50 Max. 0.50 Max. 0.035 Max. 0.20

3rd grade Min. 95.00 Max. 4.00 Max. 0.035 Max. 0.50

British

Standard

3rd grade Min. 98.23 Max. 0.65 Max. 0.064 Max. 0.033

4th grade Min. 97.40 Max. 1.03 Max. 0.095 Max. 0.033

Fig. 7: Histograms showing the average weight percentages of the magnetic and nonmagnetic components of

the50 - 100μmfractions of the studied samples.


Table 15: Standards of iron oxides content of glass sand as given by the glass manufactures*

Product Maximum Fe2O3 %

Optical glass 0.015 – 0.016

Containers (colorless) 0.03 – 0.04

Containers (amber) 0.05 – 0.08

Plate glass (general) 0.15

Plate glass (windows) 0.08

*Reported by the Ceramic Industry Magazine (1966)

Separation of heavy minerals by shaking table:

The heavy minerals (impurities) were separated using shaking table in order to concentrate quartz in the raw

material.

Conclusions:

The Lower Paleozoic Naqus Formation at the western margin of the northern part of Wadi Qena consists

predominantly of white silica sands and kaolinitic lenses. These sediments were characterized and subjected to

beneficiate in order to evaluate their economic potential. Laboratory work deals with chemical analysis,

mechanical analysis and microscope studies.

Textural investigations showed that the sands are almost entirely composed of subangular to subrounded

monocrystalline quartz grains intermixed with raredark-grey polycrystalline quartz and heavy minerals. The

heavy mineral assemblage (impurities) displays low-diversity and consists mainly of rounded to well- rounded

grains of zircon, tourmaline and traces of rutile. The surface textures of the quartz grains indicate that they are

the product of mechanical weathering while the role played by chemical weathering is absent. This makes the

raw sands for the studied sections suitable for all kinds of glass according to the American and British standard

specifications.

The textural characteristic of the studied Naqus sands indicated their suitability for glass manufacture if

subjected to beneficiation processes to increase their SiO2 content and reduce the coloring effects of oxides

particularly those of (iron, chromium, titanium etc.)as well as contaminants such as clay, organic matter, heavy

minerals etc).Hence, these sediments were subjected to several beneficiation processes to achieve the desired

“cleaned particle” and improve sand quality to meet the specifications required for manufacturing glass sands

and others products.

The applied beneficiation processes and tools include attrition scrubbing, hydrocyclone, low and high

intensity electromagnetic separator and shaking table.

Attrition scrubbing cleans sands from associate clay particles and reduces the proportion, of oxide grain

coatings. The produced attrited white sands have SiO2contents ranging from 95.23 to 99.17% (average 98.59%);

Fe2O3<0.01 to 0.06% (average 0.025%); and TiO2 0.03 to 0.12 %(average 0.072%). This indicates that most of

the clays were abraded from quartz grain surfaces. This indicated an increase contents of SiO2(from 92.85% to

98.59%) accompanied by a decrease in the proportions of Fe2O3 reduced from(0.04% to 0.025%) and

Al2O3(4.98% to 0.56%).

Appling the dry low and high intensity magnetic processes for the sands subjected to hydrocyclone process

increased the content of SiO2 to become 98.23 to 99.27% (average 98.83%), while decrease the concentrates of

Fe2O3 from (< 0.01 to 0.05 %, average 0.019%) and TiO2( 0.03 to 0.08% average, 0.045%).

The use of hydrocyclone process led to the separation of white kaolin from glass sand. Also, it resulted in

the production of higher quality of kaolin. In this case it represents a valuable co- product since its percent in

the oreapproximately11%, kaolin Ι (higher quality) and lower grade of kaolin Π. The weight percentages of

white kaolinis ~ 8-13% (average 11%). SiO2 averages 46.60% and 47.75% for kaolin Ι and kaolin Π,

respectively. Al2O3 averages 37.07% and 36.75% for kaolin Ι and kaolin Π; respectively. Dry magnetic

separation conducted on the size grade50- 100 μm produced from hydrocyclone process produced white kaolin

of a higher quality which can be used in the ceramics industry.

The obtained results revealed that attrition cleaning of the raw sands is sufficient to improve the sand

quality to meet the specifications required for silica industrial glass sands. Also, kaolin can be obtained of a

higher quality by removing the major contaminants.

The obtained results reveal that the sands after beneficiation comply with the2nd

- 9th

grades adopted by the

American Standard specifications and the 3rd

- 5th

grades given by British Standard specifications.

The produced kaolin can be used in ceramics, white cement, paper industry (filling and coating of paper)

and as a filler in rubber, paints and plastics, in toothpaste, cosmetics as well as an adsorbent in water and

wastewater treatments. Also, it can be used for the production of Metakaolin that contributes to the improved

strength, durability, chemical resistance, water absorption for quality of concrete and cement and used in glass

fiber reinforced concrete.

http://en.wikipedia.org/wiki/Toothpaste

http://en.wikipedia.org/wiki/Cosmetics


Recommendations:

The authors recommended: (1) Applying special treatments of white sand in the studied area, to produce

ultrapure elemental silicon which is used extensively, as semiconductors in „silicon chips‟ and solid-state

devices in the computer and microelectronics industries. Also, Ferro-silicon is produced for the steel and

metallurgical industries. Silicon carbides are important abrasives and also used in lasers, and the production of

silicon adhesives and sealant. (2) Conducting further studies on kaolin product especially measuring their

petrophysical properties to improve its quality to meet the specifications required for medicine industry.

All these recommendations increase the economic values to the white sand at Wadi Qena.

References

Abdallah, A.M., M. Darwish, M. El-Aref and A.A. Helba, 1992. Lithostratigraphy of the Pre-

Cenomanianclastics of north WadiQena, Eastern Desert, Egypt, In: Sadek, A. (Ed.), Proceeding of the First

International Conference on Geology of the Arab World, Cairo University, pp: 255-282.

Abou El-Anwar, E.A., and S.S. El- Wekeil, 2013. Contribution to the provenance and paleoclimate of the

LowerPaleozoic sandstones of Naqus Formation, WadiQena, Northern Eastern Desert; Integration of

support petrography, mineralogy and geochemistry, J. App. Sci. Res., 9(10): 6529-6546.

Alnawafleh, M.A., 2009. Mechanical and Physical Properties of Silica Bricks Produced from Local Materials

Australian Journal of Basic and Applied Sciences, 3(2): 418-423.

Awadh, S.M., 2010. Geochemistry of Termite Hills as a Tool for Geochemical Exploration of Glass Sand in the

Iraqi Western Desert International Journal of Geosciences, 1: 130-138.

Bandel, k., J. Kuss and N. Malchus, 1987. The sediments of WadiQena, Eastern Desert, Egypt. Journal of

African Earth Sciences, .6(4): 427-455.

Bayat, O., H. Vapur and V.I. Arslan, 2007. Upgrading Silica/ Glass Sand Concentrate Applying Cationic

Flotation, Asian Journal of Chemistry, 19(3): 1687-1692.

Blatt, H., Middleton and R. Murray, 1980. Origin of Sedimentary Rocks, 2nd

ed., Prentice- Hall, Englewood

Cliffs, NJ.

British Standard Institution, 1988. Specification for sand for making colorless glasses. BS: 2975, UK.

Carver, d., 1971. Heavy mineral separation: p. 427- 452 in Carver, R.E (ed.), Procedures in sedimentary in

petrology. Wiley- Interscience, New York, pp: 653.

Ceramic Industry Magazine, 1966. Materials for ceramic processing, 87: 137-140.

El-Bokle, F.M. and I.M. Hassanein, 1993. Sedimentological study and industrial prospect of the Paleozoic sand

deposits at southwest Sinai, Egypt, Al-Azhar Bull. Sci., 4(1): 135-152.

El-Fawal, F.M., 1994. Abu Thora Formation, west-central Sinai, facies analysis and depositional environment,

Egyptian Journal of Egypt, pp: 38.

Fathi, I., 2002. Physical and Chemical characteristics of Silica sand deposits (white sand) of WadiWatir Region,

Sinai, ActaMineralogica – Petrographica, 43: 79-83.

Hassan, A.A., 1967. A New Carboniferous Occurrence in Abu Durba, Sinai, Egypt. Proceedings of the 6th Arab

Petroleum Con., Baghdad, 2: 8.

Howard, K.T., 2008, Geochemistry of Darwin glass and target rocks from Darwin crater, Tasmania, Australia

Meteoritics and Planetary Science, 43(3): 479-496.

Indian Standard Specification, 1965. China for Ceramic Industry, Bureau ofIndian Standard (I S: 2840), New

Delhi.

Ingram, R.L., 1971. “Sieve Analysis”: In “Procedures in Sedimentary Petrology”, by R.E. Carver, Wiley

Intersciences, New York, pp: 653.

Issawi, B. and V. Jux, 1982. Contributions to the stratigraphy of the Paleozoic rocks in Egypt, Egyptian

Geological Survey, 64: 82.

Issawi, B., M. El-Hinnawi, M. Francis and A. Mazher, 1999. The Phanerozoic geology of Egypt, A geodynamic

approach .Geol. Surv. Egypt, Spec. Publ., 76: 462.

Kamel, O.A., F.H. Abdou-Soliman, M.H.M. Abd El-Maaboud, 1997. Sinai Carboniferous white sands: their

heavy mineral assemblages, fabric, geochemistry, and suitability for glass industry, 3rd

conference on

geochemistry, Alexandria, Egypt.

Khalid, A.M., 1993, Geology and geochemistry of Nuweiba area, South Sinai, Egypt, Ph.D. Thesis. Suez Canal

University, Ismailia, Egypt.

Klitzsch, E., Gröschke and W. Hermann- Degen, 1990. WadiQena: Paleozoic and Pre-Campanian Cretaceous.

In: R. Said( Ed.), The Geology of Egypt,2nd

edition, A.A. Balkema, Rotterdam, Brookfield, pp: 321-327.

Krinsley, D.H., and J.C. Doornkamp, 1973. Atlas of Quartz Sand Surface Textures. Cambridge University

Press, Cambridge, pp: 91.


Madanat, M., N. Mehyar and N.A. Zurquiah, 2006. Silica Sand: Hashemite Kingdom of Jordan, Natural

Resources Authority. Edited by Julia Sahawneh and Marwan Madanat, pp: 1-16.

Madhavaraju, J., J.C. Garcíay Barragán, S.M. Hussain and S.P. Mohan, 2009.Microtextures on quartz grains in

the beach sediments of Puerto Peñasco and Bahia Kino, Gulf of California, Sonora, Mexico, Rev. Mex.

Cienc. Geol., 26(2): 367-379.

Morton, A.C., J.R. Davies and R.A. Waters, 1992. Heavy minerals as a guide to turbidite provenance in the

Lower Paleozoic Southern Welsh Basin: a pilot study. Geol. Mag., 129: 573-580.

Mustafa, A.M.K., N.D. Bader, T.V. Khachiek, I.K. Fleah and I.G. Issa, 2011. Biobenefication of silica sand for

crystal glass industry from ardhuma location, Iraqi Western Desert, Iraqi Bulletin of Geology and Mining, 7

(1): 77- 86.

Norton, F.H., 1957. Elements of Ceramics. Addision- Wesley Publishing Co. Inc. Reading, Massachusetts.

Odewale, I.O., L.O. Ajala and D.T. Tse, 2013. Characterization of Unwana beach silica sand and its industrial

application. International Journal of Science Innovation and Discoveries, 3(1): 93-100.

OmayraBermúdez-Lugo, 2002, The Mineral Industry of Egypt, Commodity Review, U.S. Geological Survey

Minerals Year Book, pp: 121-122.

Pettijohn, F.j., 1975. Sedimentary rocks 3rd

Edition. Harber& Row, New York, pp: 628.

Ramadan, F.S., 2014. Characteristics of White Sand Deposits in Southern Sinai Region, Egypt. Middle East

Journal of Applied Sciences, 4(1): 1-10.

Said, R., 1971. Explanatory notes to accompany the geological map of Egypt. Geol. Surv. Egypt, (56): 123.

Said, R., 1990. The Geology of Egypt, Balkema, pp: 734.

Salopek, B., I. Sobota, R. Halle and G. Bedeković, 2004. Improvement of quartz sand quality using attrition

cleaning, Min planning and Equipment Selection-Hardygórva, Paszkowska and Sikora (eds), Taylor and

Francis Group, London, ISBN04 pp: 303-308.

Sundararajan, M., S. Ramaswamy and Raghavan, 2009, Evaluation for the Beneficiability of White Silica Sands

from the Overburden of Lignite Mine situated in Rajpardi district of Gujarat, India, journal of Minerals and

Materials Characterization and Engineering, 8(9): 701-713.

Wanas, H.A., 2011. The Lower Paleozoic rock units in Egypt: An overview, China Univ. of Geosciences

(Beijing), Geosciences Frontiers, 2(4): 491-507.

Weissbrod, T., 2004. A reassessment of the Naqus Formation in Sinai and the Eastern Desert of Egypt:

Stratigraphic and tectonic implications. Israel Journal of Earth Sciences, 53(2): 87-97.

Characterization and economic potential of the white...

Documents

Transcript of Characterization and economic potential of the white...