Lead into Gold - The APT Way

At US$0.97/lb the lead price is already good, but the great news is that it is soaring. Buoyed by strong Chinese demand, the future for this dull gray metal looks bright indeed.

The most abundant lead mineral, galena (PbS) has a few favourable characteristics that endear it to the processing world. The first is it’s density which at about 7.6g/cc puts it into the heavyweight class, one of the denser sulphides out there. The second is its cubic crystalline structure which results in it breaking into very convenient little cuboids, with low surface per unit mass. These attributes render galena a prime candidate for gravity concentration, the easiest and cheapest of the processing methods. The third is that it readily responds to flotation and can be selectively collected. What doesn’t therefore collect via gravity can be scalped off in a scavenger flotation step if appropriate and necessary.

Galena responds very well to gravity as evidenced by the recovery-mass pull graph in a Knelson centrifuge test:

Interestingly, the galena responds ahead of competing minerals like chalcopyrite, pyrite and sphalerite, an important consideration when it is specifically targeted from a polymetallic host.

Flowsheet

The appropriate APT flowsheet is depicted below, designed for throughputs in the 20tph range although larger capacity versions incorporating FLS Knelson CVD concentrators ahead of the spirals are possible. The use of a mineral jig up front may be justified if the galena occurs in massive form and is liberated at around 6mm crush size. Likewise, a small APT TriFloat cell may be included if the galena reports sufficiently to the fines.

Plant

APT manufactures and supplies modular packaged process plants in a number of sizes. Apart from the advantages of a low capital outlay and short manufacturing lead time, these plants require little on-site preparation and can be installed and commissioned in a fraction of the normal time required. A schematic representation of a plant suitable for galena production is depicted below. The same operating and design principles can be applied to recover other target minerals such as wolframite, cassiterite and tantalite, amongst others.

Testing

APT offers the services of our associate laboratory Peacocke & Simpson to evaluate your ore or products. The specific advantage of utilising the P&S laboratory is their ability to perform investigative work as well as process confirmation upon a larger bulk sample. Being au fait with APT plants, testing is geared towards practicality and generates the parameters necessary to enable rapid progression to plant selection and pricing.

Contract Awarded to APT for 16tph Wolframite Recovery Plant

APT are happy to announce the award of a contract for a 16tph wolframite recovery plant for Premier African Minerals. The award follows a thorough process of investigative and confirmatory testwork carried out by our associate laboratory Peacocke & Simpson that identified an efficient, but simple recovery process. This was then translated into a flowsheet and finally into a plant design that embodies the APT philosophy of elegant simplicity with high efficacy. The plant has been designed to incorporate APT’s signature stand-alone unit component modules that will be pre-assembled in their large 5000m2 assembly hall before being shipped to site for rapid re-assembly and commissioning.

“This order confirms APT’s advantages of excellent processing knowledge and smart design engineering, all in a competitively priced package”, said Chairman Keith Rayner.  “Capped off with rapid delivery we believe our offering sets a whole new standard for our industry and we are grateful to Premier African Minerals for placing their confidence in us”, said Rayner.

APT's 25000 tonne per month Classification and Gravity Recovery Circuit for Cata Mining enters Phase 2

APT has successfully completed the design, manufacture, installation and dry commissioning of a 25000 tonne per month (tpm) classification and gravity recovery circuit for CATA Mining at their site near Musoma in Tanzania. This is part of a three stage project which also includes a CIL leach circuit and field assay laboratory. Initial testwork by APT’s associate laboratory Peacocke & Simpson on various samples from around the mine area indicated exceptional grades and a high potential for gravity recovery to play a role in the process route chosen.

The design of the plant is based around a unit tower structure which contains parallel cyclones for classification of mill products and screening out of oversize material for regrinding. Gravity recovery takes place in an FLSmidth-Knelson CD20 concentration equipped with ICSj automation.

Knelson concentrates are treated in a fully automated Consep Acacia CS250 intensive cyanidation reactor with electro-winning circuit for highest recoveries. All reagent handling and dosing systems have been included with the plant.

Thanks to APT’s philosophy of providing complete modular solutions, the entire Phase 1 structure was installed within one week of the crew arriving on site, with electrical wiring and piping completed a couple of weeks later, as shown below.

Phase 2 of the project consists of 2 x 400m3 CIL Tritanks also designed by APT, and full carbon elution and electro-win facilities. These are currently complete and awaiting shipment to site and installation, after which the entire plant will be commissioned together with the third-party crushing and milling circuit.

In the meantime, APT’s field laboratory is already on site and operational (as shown below), carrying out sampling programs and resource estimations. The lab includes batch Knelson, bottle roll and AA facilities among other units.

The implementation of multiple phases of this project through APT and its associates is a demonstration of the client’s confidence in us to deliver a top level solution with minimal capital expenditure. Careful and methodical work by APT’s engineering, procurement, assembly and installation teams has allowed us to turn this into a reality.

Tritank TT20: A Small Scale Piloting/Concentrate Treatment 20m^3 TriTank, Launched by APT

Following on the back of the huge success of the larger Tritank, APT once again has designed a product to address the small scale start-up market and we are proud to introduce the Tritank TT20 to the mining industry. This is a 20m^3 CIP/CIL tankage and cyanidation system. With advanced mixing design and higher oxygen interaction the leach residence times are greatly reduced.

By analysing the leach curve of the materials, the operator can make an informed economic decision as to the required residence times of the ore. In some cases this may be as low as 8 hours resulting in a 1.5tph throughput.

The entire plant is modular and can be moved to a new site within 3-4 days. With inherent benefits like smaller footprint, less materials and batch carousel functionality,  the TT20 is the obvious choice for startup CIL/CIP processing. With six reaction compartments or sectors condensed into one conventional tank, not only is the environmental footprint smaller, but a whole host of advantages accrue to the user's benefit. Carbon is easier to move, a sector can easily be bypassed, and most important of all, the mixing efficiency is enhanced. Today, environmental impact of cyanidation use is of great concern, and this system reduces that concern and cyanidation is practiced a little more safely.

We know the idea of the Tritank is new to the industry, and although that is what makes it so special, we understand that you need to know more about it. That is why we have made video's on it, such as this one, as well as other articles on TriTank Leaching, for example. You are also welcome to email us on info@aptprocessing.com or phone on (0027) 11 704 6678.

This unit is perfect for tailings retreatment of small high grade dumps, for concentrate leach, or for pilot modules. With APT’s additional processing modules, the entire processing plant can be running within days of arriving on site.

APT - Simply smart, simply efficient. 

The APT GroundBreaker Division Are Proud To Introduce The GoldMasta Sluice To Our Product Range

As part of APT's GroundBreaker Division, the GoldMasta sluice was developed as an entry level device for artisanal miners to begin, and advance production in an efficient, affordable manner. “The engineering, design and rigorous test work coupled with the implementation of the latest technology has resulted in maximized recoveries and the production of a higher grade concentrate”, states the APT’s Director of the GroundBreaker Division. He continues, “the surface matting is easy to clean, making for a quick harvest cycle”.

The GoldMasta is made from a durable, non-corroding material and production can be commenced as soon as it arrives on site. The GoldMasta can be relocated with ease and a power outlet is not required. This allows for use in remote areas, often a requirement for exploration modules as you need to follow your mineral resource wherever it leads.

To obtain an even higher recovery, two or more GoldMasta’s can be placed in a series. This module was also engineered to work in combination with our GoldKacha concentrator (as seen in picture below), resulting in a compact package with extremely high recovery. If the full potential tonnage of the GoldKacha is required, two GoldMasta’s can be used in parallel on the tails, which you can just make out on the right of the picture below.

We also encourage you to read our article on the GoldKacha here, as it shows more on how it operates, why you need it and just simply- more on what it is!

APT do carry out demonstrations on all of our GroundBreaker plants in order to show exactly how they work, so please let us know if you are interested in us doing one in your area. We would be happy to oblige! If you are looking to become part of the APT team and be a distributor for the GroundBreaker range, please email us on info@aptprocessing.com and we'll let you know the process and benefits involved.

APT Awarded Contract For 120tph Cassiterite Gravity Recovery Plant

Appropriate Process Technologies is proud to announce being awarded a contract to design, build, supply and commission a Cassiterite Gravity Recovery based plant to process ore for the recovery of contained cassiterite. The plant will follow the winning APT formula of modular pre-assembled unit components to make for easy and fast assembly and commissioning on this remote site.

The formula was further enhanced by APT’s associate ISO9001:2008 certified mineral testwork laboratory, Peacocke & Simpson, having been contracted to undertake the process development testing upon bulk samples of the ore. “This capability again proved its worth by allowing us to quickly and effectively identify process enhancements that are incorporated into the plant design”, said APT Design and Sales Development Engineer Gary McFarlane.

This large new project is the eighth APT plant catering to non-precious metals and clearly underlines the company’s capability in this area. “We see this as a very important sector to the future of the company” said APT's representative. “We are seeing a strong upsurge of interest particularly from the tin, tantalite and tungsten processing sector and by applying our wide experience from the gold sector, where we are also very strong, we believe APT has something unique and special to offer”.

“Fortuitously APT recently completed an expansion to cater for another large project utilizing Knelson concentrators and APT Tritanks for gold recovery, so the company has the capacity to undertake this and other projects that we are currently negotiating towards”.

Watch this space for updates on this plant as we will be documenting the process, and let us know if you would like any other information regarding cassiterite recovery. You can either email us on info@aptprocessing.com, or give us a call on (0027) 11 704 6678 and speak to Gary McFarlane. We look forward to hearing from you!

Premier African Minerals Needs $4M For Mining Project

News Article

Premier African Minerals requires about $4 million to start developing open pit mining and processing operations at its RHA Tungsten project 20 kilometres South East of Hwange. PAM holds a 49 percent interest in the tungsten project while the remaining 51 percent stake is held by the National Indigenisation and Economic Empowerment Board. The mining company assigned a consultancy company to complete a Preliminary Economic Assessment of the RHA Tungsten Mine and the exercise was completed in August 2013. The mine plan presented in the PEA consisted of an open pit followed by an underground operation, with a combined life of 6 years at a Run of Mine production rate of 192 000 tonnes per year. “Economic assessment results highlight the potential of RHA Tungsten to develop an open pit mining and processing operation with a capital requirement of $4,77 million which includes a 20 percent contingency.“ Hand sorting is expected to reduce the mill feed to 5 000 tonnes per month,” said the company in a statement. PAM said CAE Mining, the world’s leading range of integrated mining solutions company has completed an update of the mineral resources taking into account an additional 12 inclined diamond drill holes totalling 1 300,7 million of drilling in the second drill campaign,which was completed in December 2013.

The mining company engaged the local mineral processing company, Peacocke and Simpson which has undertaken laboratory scale metallurgical test work to determine the most appropriate process route and to define recoveries and concentrate grade. “Subsequent to laboratory scale investigation test work carried out, additional test work has been undertaken on pilot scale upon an 800 kg sample as a proof of concept for recovery of tungsten trioxide via gravity concentration methods. The test work resulted in an overall recovery of 82, 8 percent at a final product concentrate of 63 percent,” said PAM. Since completion of the PEA, PAM approached Appropriate Process Technology for a quotation to fabricate and commission a processing plant. PAM said APT completed a plant design, a cost estimate and provided a firm quote for the supply and commissioning of the plant. The total cost is $2 million including erection and commissioning on site. PAM is currently investigating the use of the historic tailings facility as a start-up strategy for the first 12 months.

*The Herald news department was not involved in the creation of this content. 

Modular Testwork Facilities now available: APT launches Field Assay Laboratory

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APT is proud to announce the addition of a fully equipped modular testwork facilities, the field assay laboratory, to its range of modular minerals process solutions. As with all APT plants, these laboratories are pre-specified and supplied in “quick-fit” kit form to allow rapid manufacturing on site and to make them quickly and easily trans-locatable for exploration companies.

APT is initially launching 3 variants of laboratory, all of which are housed in a 9 x 9 m open-sided roof structure with drop-down sides to take advantage of breezes in hot climates, and provide protection against the elements when required. The structure is pre-wired with plug ‘n’ play electrical reticulation and pressurized water distribution systems, and where necessary instrument air systems, all part of APT supply. The customer simply needs to supply a slab on which the structure is erected by an APT team, add water to the tank and power to the distribution board, or alternatively diesel to the APT-supplied gen-set.

All lab variants also include a purpose-design, insulated, vented and air-conditioned containerised section for wet chemistry, final analysis and sterile conditions.

Each lab type includes sample preparation from jaw crushing to pulverising, sample splitting and pressure filtration of pulp samples. These sections are housed in the main shed, with water washdown points, wet areas, shelving and sample storage, etc. The diversification begins downstream of sample preparation.

The GOLD EXPLORATION MODULE is supplied with milling and gravity concentration equipment to deal with and account for nugget effect, and bottle-roll BLEG systems with AA Spectra finish, at up to 200 samples per day. The field lab deals only with recoverable gold, but BLEG residues can be sampled for off-site assay to provide a recoverable gold/total gold factor.

The GOLD LEACH PLANT MODULE takes the exploration module one step further with the inclusion of activated carbon assay and equipment for monitoring of gold leach plant operation.

The NON-GOLD MODULE is provided with EDAX X-Ray Fluorescence analytical facilities for dealing with a wide range of elements from base metals to industrial minerals. Detection limits vary, and for very low-grade applications APT can supply concentration systems to allow target elements in ores or soils to be upgraded to detectable ranges. After all, if it doesn’t upgrade in a lab, it’s not going to upgrade in a plant, so pack the lab and move to the next target.

All APT FIELD ASSAY LABORATORIES have several sub-systems in common, allowing APT to use top quality equipment at competitive prices, and making the modules accessible to even modest mining and exploration operations. Gone are the days of drilling or digging or sampling, and then waiting days or weeks for result. APT puts the power of quick-turnaround assays into your hands.

Target Many Minerals Besides Gold: APT plants do just that

Whilst gold remains the main target for miners, particularly at the smaller scale, the allure of many of the base and specialist minerals like tin and tantalite is becoming stronger. APT is experiencing an unprecedented interest in base and specialist mineral plants from virtually all geographical areas of the globe, and so the hunt to target many minerals has begun. Price trends

Not only are the prices of these minerals attractive, but demand is strong and the upward trend is likely to continue. To put the value of producing tantalite concentrate into context, let us consider an ore with a hypothetical recovery yield of 1000 grams per tonne of tantalite concentrate. The recovery value of this tantalite would be of the order of $207 per tonne, equivalent to a gold recovery of about 5.2 grams per tonne Au!

This modest tantalite recovery would therefore constitute a very viable mining proposition. Similarly, recovery of tin, tungsten, chromium and other bulk minerals offer attractive returns.

*Acknowledgements to InfoMine

Occurrence

Many of the mineral concentrates occur in the upper oxide environment where they are relatively easy to mine and extract. Deposits are well known and many are being actively targeted by artisanal miners. The more valuable bulk minerals like cassiterite (tin), tantalite, wolframite (tungsten) and chromite readily concentrate in the natural environment, so alluvial and elluvial deposits are commonly worked.

Processing

All of the minerals referred to above have high specific gravities relative to the host and are therefore easy to recover and concentrate via gravity. Gravity methods are employed universally by artisanals to recover these minerals from rivers and rubble beds. APT process flowsheets take account of the mineral species present, their degree of liberation and the particle size distributions. Although the final result is clean and simple, a great deal of thought goes into achieving this result. Where crushing and milling is necessary, the appropriate modules are inserted. Attached below is a flowsheet for the recovery of course and fine tantalite from an alluvial material.

APT Plants for bulk minerals

APT has developed a range of plants specifically to target the high value bulk minerals. As with all APT plants, these units are simple, robust and offer excellent value for money. Energy requirement has been kept to an absolute minimum so that generators can be used to power the entire process. The plants are available in a range of sizes; 10, 20, 80, 250tph and can be configured with APT’s famous RG scrubbers to target alluvials and loose matrix only, or they can include a crushing and milling section as appropriate.

Testing

APT is primarily a mineral processing company who manufactures its solutions, rather than a just an equipment manufacturer. We have a vast experience in mineral processing and our associate laboratory Peacocke, Simpson and Associates, has over 29 years of experience in testing ores and feed materials. Our emphasis is upon innovative, smart solutions to result in the desired result without simply defaulting to conventional systems. Solutions are therefore not only functional, but minimalistic and efficient.

APT plants: target many minerals besides gold. 

Mobile Exploration and Production Kit Now Launched by APT

The above mobile exploration and production kit has now been launched by APT. 

The aim of this minerals recovery and exploration kit is found in taking small and medium scale exploration and production to a new level, and enabling smaller mines to grow and develop on a more suitable budget, without compromising on quality but rather creating something better than what is out there today. This goes hand-in-hand with our philosophy of not only creating equipment, but rather creating solutions to problems faced in the industry today, and furnishing the smaller scale mining sector with plants that can take them to the next level.

The RG30-T Production Kit allows optimal mobility by means of a complete mining kit mounted on a rugged trailer. The concept behind the mobile solution was driven by the need for reducing the risk and costs involved in the exploration process, while enabling greater production and therefore optimum profit to be made. Furthermore, it enables the operator to anticipate future stumbling blocks in the mining process ahead of feeding to the main plant, by providing the ability to process large bulk samples through to small concentrates.

The Exploration and Production Kit combines the RG30 and GoldKacha Mark 4, with Goldkonka Up- Grader and GoldJigga Field Jig and ancillary equipment, into a robust configuration which fits onto a neatly designed trailer, allowing you to move from resource to resource. The RG30-T is a fully functioning system and does not require interface with other machinery.

The process begins at the RG30 scrubber, and the leading features are outlined here. Firstly, the GoldKacha takes larger mass pull to concentrate than competing equipment, therefore a very high primary recovery is achieved. The RG30 also has a deep belly drum together with an integral high efficiency trommel screen, allowing for both clay disintegration and the improvement of gold liberation from host material. The feed from the RG30 scrubber is then passed to the GoldKacha Concentrator via gravity, eliminating the need for additional pumps.

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