MODULAR/KIT GOLD STRIPPING PLANTS

‘CLIENT SATISFACTION IS OUR SUCCESS’

C O M OE N G I N E E R SS P E C I A L I S T E Q U I P M E N T

MODULAR & KIT ELUTION SYSTEMSOver the past 27 years, Como Engineers has become a recognised leader in the design and construction of modular containerised gold desorption (elution), carbon regeneration and gold refining systems.

Using our extensive technical and practical experience, Como Engineers Specialist Equipment Division have developed proprietary technology to provide equipment that out performs any similar technology currently on the market.

These fully furnished plants can be broken down into minimally de-constructed units and containerised, then shipped anywhere in the world. Reassembly typically takes around 2 weeks for modular plants (subject to the size of the unit) and the client simply needs to terminate reagent supplies, power and feed and return lines to the system in order to begin commissioning and operation of the equipment.

REST ASSURED YOUR DESORPTION PROCESS WILL WORK

With the extensive experience Como Engineers has in the areas of desorption, carbon regeneration and refining operation and design, you can be satisfied in the knowledge that the system you receive from Como is optimised for your process and will operate efficiently and effectively. Como’s elution systems are the bench mark for high recovery - rapid desorption and electrowinning of any system on the market.

Como will undertake the full detailed process, mechanical, electrical and control engineering design with minimal design frustration for your company. We will then fabricate, trial assemble and wet commission your unit prior to it being shipped to your gold project.

MODULAR (1-10T) - SAVING YOU TIME & MONEY

Delays in construction on site may translate into expensive cost overruns and project short falls. Como Engineers’ MODULAR plants can help reduce or negate this aspect of your project by providing you with a fixed price - fixed time - guaranteed product in a modular form, that can be readily installed at site with minimal equipment, materials and labour.

KIT PLANTS (8-20T) – FLEXIBILITY & EASE OF MAINTENANCE

Based on a ‘kit’ supply rather than pre-assembled modules, the Como KIT Plants provide a fully distributed approach to the elution, carbon regeneration and goldroom installations. Where traditionally systems would need to be designed by an engineering firm and then procured from several suppliers, the KIT Plants provide all of Como’s extensive system design knowledge in one convenient package that still provides the performance that you’d come to expect of a Como elution plant, but with more space and the ease of maintenance of a custom built system.

PRESSURE OR ATMOSPHERIC ZADRA

Como Engineers has refined the Zadra elution process and optimised it to run with the highest efficiency through proprietary system designs which optimise system flows, elution temperatures, electrowinning cell and rectifier designs and reagent combinations. When coupled with our interactive touchscreen Automation Package, the batch operated plant can complete both elution and electrowinning cycles combined in as little as 8-10 hours.

Designed to be robust, fast and effective, the Zadra process is your first choice in a desorption design, having a lower capital and operating costs, a smaller footprint compared to the AARL elution process, and it’s a little more than forgiving if your site suffers from poor water quality.

INTEGRAL PRESSURE STRIP (IPS)

Como Engineers introduced the first Integral Pressure Strip elution circuits to the market in the late 1980’s having developed the production plant in conjunction with metallurgist Ken Baxter in Perth, Australia.

The proprietary design provides the fastest desorption and electrowinning cycle available on the market, with a 5-8 hour cycle duration. By pressurising the electrowinning cell, the gold-cyanide complex in electrowinning is destabilised and increases the electrowinning efficiency, lowering solution tenors returning back to the elution column and providing the optimal kinetics for rapid eluting of the precious metals off the loaded carbon.

With the additional benefit of low energy losses from the system as a consequence of the absence of a de-pressurising stage (as occurs in the Pressure Zadra process), it’s also the most energy efficient of all the stripping processes.

AARL

Traditional and Split AARL designs are available for the more traditional gold-cyanide elution process.

OPTIONS, SUPPORT AND SPARE PARTS

All systems can be provided as complete carbon elution, regeneration and goldroom packages or you may opt to select only one of these modules. These items can be ordered as upgrades to existing brownfields circuits or for new sites. Como Engineers also supplies all your gold equipment needs, including the popular stainless steel electrowinning cells, rectifiers, carbon regeneration kilns and gold barring furnaces, or whatever else you require.

Como Engineers can also provide you with the technical expertise to assist in both on-site erection of the plant, commissioning and operator training.

SOME RECENT INSTALLATIONS:

Client: Banro Corporation, Twangiza Operations, DRC; 3 tonne automated PLC controlled Pressure Zadra System with carbon regeneration structural and goldroom, 2013Client: Co Company, Tiouit Operations, Morocco; 2 tonne automated PLC controlled Pressure Zadra specified for silver-gold recovery with containerised goldroom, 2013Client: Agnico Eagle, Laronde Operations, Canada; 8 tonne automated DCS controlled Pressure Zadra System with 500kg/hr natural gas carbon regeneration kiln, fine carbon recovery, transfer water system and goldroom, 2013Client: MCC, Sudan Pilot Plant, Sudan; 2 tonne manual Pressure Zadra elution plant with modular containerised goldroom, 2012Client: Metso Minerals SALA, Nordic Mines Laiva Plant, Finland; 6 tonne automated PLC controlled Pressure Zadra system with 300 kg/hr LPG carbon regeneration kiln, transfer water tank and fine carbon recovery system and collapsable goldroom, 2011

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For more detailed information and technical specifications please contact: martin.smith@comoeng.com.auor spares@comoeng.com.au

ELUTION MODULE

Metso Minerals - Nordic Mines GoldProject, Laiva Finland

The elution and regeneration plants are available in either relay controlled operation with manual valves or full batch PLC control with touchscreen operation and include:

Acid Wash Column with direct acid injection manifold and HCl acid dosing pump•

Thermally lagged Elution Column with integral carbon filters•

Como’s proprietary ‘Direct Eluate’ heating circuit (indirect available as option only to 120�C operation) with fuel fired package burners available in LPG, Natural Gas or Diesel. Electric direct heating is also available as an option

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Skid mounted thermally lagged reagent tank(s)•

Control system (Basic option - relay/programmable controller operation or full PLC batch control with automation of valves)•

Electrowinning cells located in secured electrowinning room•

SCR or Switch Mode Rectifiers•

All Piping and Instrumentation•

Available in sizes from: 1 tonne – 10 tonne carbon capacity in MODULAR form or 8 tonne – 20 tonne carbon capacity in KIT form

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Como Engineers were engaged by Agnico Eagle, based in Cadillac Quebec, for the detailed engineering design and equipment supply for the elution, regeneration, goldroom and carbon recovery systems of their Laronde Deep Mine project.

To be located at their existing mine processing facility located in the Abhitibi region of Quebec, Como was also responsible for the supply of much of the process equipment, including our proprietary designed ASME elution and acid wash columns (8 tonne capacity), our ESF series stainless steel range of electrowinning cells, quench tank pressure vessels, a 500 kg/hr Custom Furnaces Carbon regeneration kiln and ancillary accessories.

Agnico Eagle is a previous client of Como Engineers having utilised one of Como’s automated elution and regeneration packages on their Lapa mine in the same region in 2008.

Laronde Deep Mine - Agnico Eagle Laronde Deep Mine Project, Canada

Como Engineers supplied a 3.0 tonne Modular PLC automated Pressure Zadra Elution System with integral Goldroom, and including Carbon Regeneration Structure.

The plant was fully constructed, assembled and hot run tested in Perth, prior to being dismantled and shipped to site in nine 40’ sea containers.

The system included a 700kW Direct Eluate Heating system with full PLC control of all elution and electrowinning process steps. The system allows for client customisation of the system control interface to allow for the site’s primary language for the system operation.

This system was manufactured to Como’s latest design, and included new enhancements for improved operability.

Banro Corporation - Twangiza Gold Project, Democratic Republic of Congo

Como Engineers were engaged to supply a 6 tonne PLC automated Pressure Zadra System with 300kg/hr LPG fired carbon regeneration kiln and integral goldroom.

The plant is the most modern of Como’s MODULAR designs and was designed in accordance with strict European EU Directives with fully audited Quality Control Documentation assessed by EU Notified Body - Lloyds.

The system included a 1500kW Direct Eluate Heating system with full PLC control of all elution process steps, plus a 300kg/hr LPG fired regeneration kiln with twin quench tank system. The Metso system also introduced the collapsing modular goldroom system which allows modules to be interconnected to make a goldroom of any size to client’s specifications.

GOLDROOM MODULE

Como Engineers is proud to have a long history as distributor for the class leading carbon regeneration kilns from Custom Furnaces. All Como MODULAR or KIT systems are based around integrating a Custom Furnaces horizontal rotary kiln, which complements Como’s Elution design performance by achieving high regeneration performance of the eluted carbon to greater than 90% activity.

The kilns are designed around proven process design fundamentals with attention in design to ensuring sufficient thermal conduction of heat to the carbon occurs. This is achieved by providing adequate thermal area in the retort tube, with a suitable lifter design for gentle bed agitation and a minimum of 20 minutes retention time at hold temperatures. Coupled with ensuring that a reducing steam atmosphere is present throughout the regeneration process and that re-contamination of cold carbon with by-products of pyrolysis does not occur by utilising a co-current exhaust flow design, ensures that product regeneration is optimised.

Available in LPG, Diesel, Natural Gas or Electrically fired configuration.

Custom Furnaces

The regeneration plants are available in relay controlled-manual valve operation or with full PLC operation and include:

Custom Furnaces horizontal regeneration kiln (LPG, NG, Diesel or Electric fired) •

Coded (ASME, BS or AS) pressurised carbon quench tank•

Elevated regeneration kiln support structure (floor mounted system available on request)•

Carbon feed hopper with access platform•

Barren carbon dewatering screen (DSM design best suited for this application)•

Dry or wet carbon sizing screen•

Local relay based control system with optional PLC module and touchscreen•

All Piping and Instrumentation•

Available in sizes from: 50 kg/hr to 1400 kg/hr •

Como Engineers were engaged by Agnico Eagle, based in Cadillac Quebec, for the goldroom design for their Deep Mine project.

The 8T elution plant goldroom is based around Como’s KIT plant design which provides for a two level structural goldroom with the lower floor accommodating the gold processing equipment and optional laboratory space, with a second floor dedicated to the electrowinning cells.

All security screens, structural columns and beams and piping are pre-fabricated and fully containerisable. The second floor level can be provided as either a chequer plate bunded area, or alternatively Como can supply Bondek for site supplied pouring of concrete or a third option of hollowcore pre-fabricated beams which then require only site casting of a sealing layer of grout.

Kit Goldroom

Como supplies both MODULAR collapsing goldrooms or full multi-floor structural KIT goldrooms providing all the required equipment for gold processing and refining and can include:

Optional locating of electrowinning cells and rectifiers•

Pendant controlled gold barring furnaces A100-A1000 (LPG, NG or Diesel) complete with extraction system•

Calcine Ovens with extraction system•

Gold Safes•

Work and scales benches•

Cupellation furnaces if needed•

Tooling (needle guns, polishing/buffing equipment/drill presses etc.)•

Optional security monitoring system pre-fitted•

Cathode wash bays•

REGENERATION MODULE

OPTIONAL EQUIPMENT OVERVIEW

The Fine Carbon System, Carbon Transfer System and Sludge Processing System provide enhancements to the operation of your Como elution/regeneration plant.

Comprises an agitated conical bottom vessel with transfer eductor, fresh carbon feed chute and electric monorail for supply of the carbon to your CIL/CIP/CIC circuit. Gentle agitation reduces the carbon fines introduced into your adsorption circuit.

Fresh Carbon Conditioning System

Como’s pressurised hydraulic transfer for carbon movement through the elution and regeneration systems reduces carbon attrition and hence fine carbon losses when compared with other recessed impeller pump transfer methods. The transfer water recovery system incorporates a large transfer water vessel (settling design) with a transfer water pump system providing the motive water for carbon transfer around the plant. Transfer waters that transport carbon over screens or sumps are returned to the transfer water tank and recycled, lowering your plants overall water use.

Transfer Water Recovery System

Used in conjunction with the Transfer Water Recovery System, this design bleeds a constant stream of recovered transfer water through a plate and frame recovering a high proportion of the gold bearing fine carbon developed through the CIL plant. In CIL/CIP systems where the loaded carbon is pumped by loaded carbon transfer pumps (rather than utilising air lifts for carbon movement) floating fine carbon often reports to the elution system along with the loaded carbon. This carbon is usually higher in gold and precious metal loadings when compared with the carbon that is stripped. The quantities of fine carbon that can potentially be recovered (per tonne of loaded carbon processed) can be of the order of 40kg per tonne per week, potentially amounting to a considerable amount of additional gold recovery that would otherwise report to tails.

Fine Carbon Handling System

Como has developed an effective system of recovering gold sludge from the electrowinning cells and cathode wash bays when stainless steel mesh sludging is utilised in the electrowinning circuit. Incorporating a sludge settling tank, plate and frame filter and transfer pumps, this equipment operates in a closed circuit to separate the fine carbon dendritic sludge from the eluate permeate. The resulting cake is firm, compact and with low residual water that enables low temperature oven drying and dore processing rather than having to deal with decanting methods or cumbersome pressure pot filters.

Gold Sludge Processing System

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C O M OE N G I N E E R SS P E C I A L I S T E Q U I P M E N T