Dedicated to the art and science of Mining Minerals technology

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1 TechNewsMarch 2018 Dedicated to the art and science of Mining Minerals technology

2 TechNews Index 2

3 TechNews Welcome letter 3 Letter from Mining Solutions First, we would like to thank all our customers for the long-term partnership and look forward to establishing strong and enduring relationships with our new partners in As we reflect on 2017, we should highlight the LIX Users Conference in Valle de Colchagua, Chile. This is a tangible expressions of our commitment to knowledge exchange and networking opportunities that foster development in process and technology areas in solvent extraction. The collaboration among more than 100 participants from 16 countries across the industry was excellent and BASF is proud to support initiatives that promote such engagement. For 2018, can see that demand is still growing for mining and mineral processing to reduce its impact on the environment. This includes air pollution, mine pits or the contamination of water sources and the disruption of water tables. Communities around the world are exerting more influence on mining activities through approval processes. The consequences for miners will transform their operations. For example, China is introducing fees for the disposal of each ton of mine tailings and Brazil is considering doing the same thing. Both countries have experienced tailings dam failures in the last few years and are looking for ways to pay for the environmental damage and prevent it happening again. efficient agricultural processes is increasing, we have made and will make a series of investments in all aspects of phosphate production. This gives our Technical Experts additional opportunities to help our customers improve their flotation processes, not only in Russia but also in North Africa and the Middle East. Mining chemicals suppliers like BASF will need to help their customers to find solutions for these environmental trends. This is why, in February, BASF expanded the existing Mining Solutions footprint within the Mintek Campus in Johannesburg, South Africa, and celebrated the official opening with more than 60 customers. The binder briquetting laboratory is dedicated to Alcotac and the repairing of environmental damage. We hope you will find this latest edition of Tech- News informative and that it provides some valuable insights for your business. We look forward to sharing more relevant information with you over the coming year, in this newsletter as well as on our website and LinkedIn page. Best regards, In Central Africa, we look forward to continuing to assist our customers in increasing copper production. We will do this by providing them with superior hydrometallurgy technical services and improving their efficiency and capabilities for future competitiveness. Because demand for Michael Schwarz Regional Business Management Mining Solutions Europe, Middle East and Africa

4 TechNews Dewatering / Filtration 4 Advanced dewatering and filtration solutions: Drimax filter aids for iron ore fines Scope Drimax reagents are used to aid the removal of residual water from the filter cake formed when dewatering a range of different mineral slurries. Dewatering of iron ore fines (< 0.5 mm) has become a regular topic of discussion due to an increase in wet beneficiation processes used to upgrade lower-quality ore deposits, increased water content in ore bodies located below the water table and an increasing focus on transportable moisture limits (TML). Significant improvements are possible with the use of filter aids, usually anionic surfactants and flocculants. Filter aids used correctly can improve cake permeability, in turn decreasing cake formation times and increasing filtration rates. In addition to increased throughput, savings and benefits for producers can include reduced moisture limit penalties and improved handleability, along with energy and water savings. The results of a BASF study on the effect of filter aids on the dewatering of iron fines is presented below. TML is the maximum total water content allowed for a given material to be transported to ensure that liquefaction does not occur. The most common mode of transport for iron ore is sea bulk cargo and the liquefaction of bulk cargo in ships presents a significant safety issue. The ability of water to drain or separate more readily from iron ore fines (IOF) can be linked with the type of association the water has with the solids. The water associated with IOF can be grouped into three categories: Water that has little relationship with the iron ore, and can be easily removed. Water which is closely related to the particle surface and the extent of its removal is affected by the surface physics and surface area of the iron ore. Water held internally within the iron ore, which is related to the porosity of the ore. In dewatering and filtration applications, loosely associated water is easily removed while water held within the IOF is unable to be removed, hence performance of the process is dictated by the extent to which water is associated with particle surfaces and particle contact points. Anionic surfactants reduce the surface tension of the associated water, which is then removed more readily leading to improved filter cake moistures. In previous studies, two types of vacuum filtration test have been examined; rotary (disc and drum) and horizontal belt types. Rotary vacuum filtration test work usually involves the use of a filter leaf apparatus (Figure 1a). This is designed to simulate solids pick-up and cake formation, which is the crucial aspect for disc and drum filters. A study by Sanstry et al 1983 used a filter leaf test method and found that flocculant addition was effective in improving cake yields but had little impact on moisture content. For horizontal belt vacuum filtration test work, a simple vacuum is applied to the treated slurry, and water is drawn from the sample (Figure 1b). For horizontal belt vacuum filtration, the rate of dewatering and filter cake moisture contents is of the highest concern. Filter leaf Flocculated slurry Filtrate Fig 1. a) Vacuum filtration using a filter leaf. Vacuum gauge To vacuum pump Flocculated slurry Vacuum gauge Filtrate cloth Filtrate To vacuum pump b) Vacuum filtration setup for horizontal vacuum filters.

5 TechNews Dewatering / Filtration 5 Study Objective The aim was to investigate the effect of BASF s Drimax filter aids on filter cake moisture content of two iron ore fines samples from the Pilbara region of Western Australia using a lab-scale vacuum filtration unit. Experiment Plan Sample and preparation methodology Samples were collected from two sites in the Pilbara region of Western Australia, just prior to the feed entry onto the vacuum belt. Sample 1 = 60% w/w Sample 2 = 64% w/w The two surfactants used were BASF s Drimax 1234 and Drimax 1239NF, both liquid, sulphosuccinate diester based products. The surfactant solutions were prepared and dosed at 1% w/v. The flocculant used was BASF s Magnafloc 5250, which is an anionic 25 mol% polyacrylamide sodium acrylate product. The polymer's molecular weight distribution is well suited for filtration applications. The flocculant solution was prepared at 0.25% w/v then further diluted to 0.025% w/v prior to testing. Filtration Methodology Vacuum filtration tests on IOF are primarily used to determine the most effective chemical treatment and the optimum dose rates for each site application. For this test work, a bench-scale vacuum filtration setup was used (Figure 1b). The two samples were tested with no chemical addition, a blank. The surfactant dose rates were then varied. Sample 1 only required a surfactant addition. Sample 2 required an addition of flocculant into the matrix due to its high fines content and particle size distribution. Without the flocculant addition, sample 2 had a long cake formation time. The Drimax surfactant products were directly dosed into the feed solution and mixed for 15 seconds prior to entry into the Filtratest unit. Dose rates for the test work in relation to the surfactant ranged from 29 g / t to 153 g / t. For sample 2, the flocculant was dosed prior to the Drimax addition with a 15 second mixing interval in between additions. Filtration time given for the complete test was 150 seconds for both ore samples, which corresponded to plant operating conditions. The filter cake produced was weighed in an aluminium tray and dried in the oven at 105 ºC for two hours. The cake was then re-weighed and the moisture content of the filter cake was calculated. Experiment Results The effect of filter aids on two iron ore fines samples were evaluated using a lab-scale vacuum filtration unit. The first sample showed a reduction in the filter cake moisture content of 2.3% w/w with the use of BASF s Drimax For the second sample, a reduction in the filter cake moisture of 3.4% w/w along with an increase in filtration rate of 20% was achieved by using a combination of Magnafloc 5250 and Drimax 1239 NF, as both filter throughput and cake moisture were considered important by site. Sample 1 60% w/w A relationship between surfactant dose rate and filter cake moisture content (Figure 2) was noted for sample 1. As the surfactant dose rate increased, the filter cake moisture decreased. Filter cake moisture content (% w/w) Surfactant dose rate (g/t) Fig 2. Surfactant dose vs filter cake moisture content. The untreated or blank sample displayed a final moisture content of 23.6% w/w compared to the material treated with Drimax 1234, which achieved a final filter cake moisture content of 21.3% w/w with a dose rate of 125 g / t. This equate to a 2.3% absolute reduction in filter cake moisture. The trends also suggest in Figure 2 that a further increase in surfactant may achieve further moisture reduction.

6 TechNews Dewatering / Filtration 6 Sample 2 64% w/w A flocculant addition was required for Sample 2 to help with filter cloth blinding. The flocculant was first dosed alone, with the optimum dose rate found to be 0.7 g / t (Table 1). A filter cake moisture reduction of 2% absolute was observed at the optimum flocculant dose rate of 0.7 g / t. Dosing beyond this, a negative impact on filter cake moisture was noted. The solids throughput rate was increased by 20% with the addition of flocculant at a dose rate of 0.7 g / t, from 650 kg/m²/ h to 780 kg/m²/ h. Overall, a trend in solids throughput was seen to increase as the flocculant dose rate increased. However, the inverse was seen in relation to filter cake moisture content. A further reduction in moisture was required for site and therefore the addition of a surfactant after adding the flocculant was included. The optimum flocculant dose rate was determined at 0.7 g / t, therefore a dose response curve for the Drimax 1239NF, was performed. With the addition of the Drimax 1239NF a final filter cake moisture reduction compared to the blank was 3.4% absolute (Table 2). Dosing above the optimum surfactant dose rate had a negative impact on filter cake moisture content. Product Flocculant dose Rate (g / t) Table 1. Results summary sample 2, with flocculant addition. Cake moisture (%) Blank Magnafloc 5250 Product Flocculant dose Rate (g / t) Surfactant dose Rate (g / t) Cake moisture (%) Solids capacity (kg / m²/ h) Blank Magnafloc Drimax 1239NF Solids capacity (kg / m²/ h) Conclusions The use of an anionic flocculant and surfactant successfully dewatered two iron ore fines samples from the Pilbara region of Western Australia. Both vacuum filtration applications produced a lower filter cake moisture content when the surfactant was applied. The second sample required an addition of flocculant, which improved the solids throughput rate on the vacuum belt by forming a more permeable filter cake. Overdosing either flocculant or surfactant had a negative impact on filter cake moisture content. Solids throughput capacity improved with increasing flocculant addition but inversely impacted filter cake moisture content. References Sastry K, Kawulok-Englund D & Hosten C, Comparative study of the vacuum filtration behaviour of iron ore concentrate slurries, Society of mining, metallurgy & exploration, Technical note; pages 1,432 1,436. Drimax products may be added either directly to the filter feed or to wash water applied to the filter cake via spray bars. It can be used in a wide variety of mineral slurries from industries including alumina, copper, nickel, gold, iron ore, sand and coal. Table 2. Results summary sample 2, with flocculant and surfactant addition.

7 TechNews Lupromin FP A Lupromin FP A 105: environmentally friendly phosphate flotation reagent The functioning of modern society relies entirely on effective agriculture, which is almost entirely dependent on the availability of the critical elements in the soil. Phosphorus is present in all living things and is required for cell growth. Together with nitrogen and potassium, it is one of the most important elements for plant life. In agriculture, the growth of crops is dependent on the phosphorus content of soil and is limited by it. Around 90% of global phosphate mining is used for food production. The production of phosphate fertilizers relies on cost-efficient beneficiation of apatite ores, which often requires direct or inverse flotation. The efficiency of the flotation stage is defined by the flotation reagent used. While the typical reagents are based on long-chain fatty acids (e.g. oleic acid or tall oil), modification by a surfactant significantly improves the selectivity and collecting power of a fatty acid collector. One commonly used type of modifier in phosphate flotation are alkylphenol ethoxylates, whose performance has made them indispensable in the phosphate industry over the last 50 years. However, these substances when released into the environment decay to toxicologically problematic alkylphenols and are therefore banned or being phased out in most legislations. As the leading producer of specialty surfactants, BASF has developed a class of environmentally friendly replacement reagents that outperform APEOs as flotation reagents. Each plant requires its own tailor-made reagent composition, which can be optimized using statistical modelling of the system and determining the optimum performance point (Fig. 1). Fig. 1: Optimization of a flotation reagent composition for a sedimentary phosphate ore sample.

8 TechNews Lupromin FP A This flotation reagent concept has been applied to the apatite flotation stage of the igneous deposit at Kovdor (Russia). (Fig. 2). A reagent composition (Lupromin FP A 105) was optimized in the course of lab and pilot-scale trials on site before a full-scale plant trial in conjunction with a tall oil fatty acid as main collector (Fig. 3). While the effective dosage of the reagent can be reduced to g / t compared with 240 g / t of the APEO-based incumbent reagent, the average P 2 O 5 recovery at the target grade of 37% P 2 O 5 increases by 2.5 3%. This finding has subsequently been confirmed by repeated double-blind tests on parallel flotation lines. The precise control of hydrophobic-lipophilic balance (HLB) in multicomponent surfactant modifier systems can lead to improved flotation plant performance for phosphate ores, yielding: Improvements in both recovery and grade Reduction in collector dosage rate Reduced collector costs Downstream processing benefits P 2 O 5 recovery (%) Open pit mine Polymetallic ore Magnetic separation Iron concentrate Apatite concentrate Direct apatite flotation Gravitation beneficiation Baddeleyite concentrate Tailings Concentrate grade (% P 2 O 5 ) Lupromin FP A 105 Incumbent modifier Fig. 3: Performance comparison between Lupromin FP A 105 and incumbent at Kovdor flotation plant; each point signifies the average of an 8 h shift. Fig. 2: General process scheme and flotation plant at Kovdor.

9 TechNews LIX Users Conference 9 BASF Mining Solutions thanks Antucoya and all attendees of the LIX Users Conference 2017 In November 2017, BASF s Mining Solutions team gathered with customers and other industry experts from all regions to exchange experience, share ideas and technical concepts at the LIX Users Conference This version of the biennial event was held in Santa Cruz, Chile. More than 100 participants from 16 countries attended this well-established international forum for hydrometallurgy. Over three days, 30 presentations focused on the challenges facing the mining industry in general, current and future challenges in hydrometallurgy and new leaching methods were held. After the conference, many attendees flew to the north of Chile and visited the Antucoya hydrometallurgical operation. BASF sincerely appreciates the effort of all conference participants who traveled to Santa Cruz in Chile. The many presentations and the attendees participation in the discussions contributed to making this conference an enriching event. BASF wishes to express its gratitude to Antucoya (Antofagasta Minerals S.A.) for the excellent organization and an insightful plant visit. The BASF Mining Solutions team looks forward to welcoming you to our next LIX Users Conference. Felipe Schneider, Regional Business Management Mining Solutions South America, welcomes participants to the LIX Users Conference 2017 in Chile. Plant visit to the Antucoya hydrometallurgical operation in Chile (by courtesy of Antucoya).

10 TechNews Mining fairs 10 Meet us at mining fairs in 2018 Phosphates Marrakesh / Morocco March PASTE Perth / Australia April Mining World Russia Moscow / Russia April Expomin Santiago / Chile April ALTA Perth / Australia May Publishing information Publisher: BASF SE Ludwigshafen Germany Phone: th World Mining Congress Altana / Kazakhstan June Hydroprocess Santiago / Chile June Southern African Base Metals Conference Victoria Falls Livingstone / Zambia July AUS IMM Brisbane / Australia August Authors: S. Dickie A. Geiger T. Haskell Y. Joe H. Kalitzky A. Michailovski Alumina Gladstone, Queensland / Australia September Dubai Mining Show Dubai / VAE October Australian Coal Preparation Conference Brisbane / Australia September IMPS Antalya / Turkey October Expomina Lima / Peru September Congreso Internacional Minero 2018 Sonora Sonora / Mexico October XXIX IMPC Moscow / Russia September Procemin Santiago / Chile November Pictures: istockphoto Getty Images All other pictures: BASF Published: March 2017 Art direction and design: mangler+noller GmbH Dantestraße Heidelberg