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By Nakahiro Y, Wakamatsu T

In the present study, from experimental results, a new concept of possibility of flotation separation of quartz from feldspar is presented. The effect of the nonionic surfactant Brij 58 on the flotation behaviour of quartz and feldspar has been investigated. The effect of the surfactant adsorption at the solid-liquid interface was also studied. The results demonstrate that maximum flotability of quartz occurred at low concentration of surfactant. Feldspar is not collected by this surfactant. Flotation tests with feldspar that had previously been subjected to leaching by hydrochloric acid yielded similar flotation response as that of quartz. The effect of removal of alkali cations from feldspar surface on its flotability was investigated. The effects of inorganic and organic additives on the flotation recovery of quartz are discussed in terms of the slating-out or salting-in properties of these additives. KEYWORDS: Alkyl polyoxyethylene; feldspar; flotation; nonionic surfactant; quartz; salting-in; salting-out; separation; silanol groups.

Jan 1, 1993

By Leming Ou, Longsheng Yi, Qiming Feng, Yiping Lu, Qing Shi, Kun Liu, Guofan Zhang, Yanfei Chen

"Three important components of stirred tanks involved in energy consumption, the impellers and baffles, were investigated to intensify the agitation pretreatment on the flotation of nickel ores. Flotation tests revealed that the stirred tanks with two impellers had an advantage over those with one impeller in intensifying agitation pretreatment, and the higher agitation speed led to better flotation performance of nickel ores. Installation and removal of baffles were also employed in the stirred tanks, and flotation tests demonstrated that with baffles, the flotation grade increased significantly. These agitator design improvements were used to demonstrate that the energy supplied to the system significantly influences the flotation recovery and that if the energy consumption of the agitation pretreatment is ideal, flotation efficiency can be improved. Data from full-scale operations backed up these results.INTRODUCTIONThe flotation recovery of nickel-copper sulphide ore at the Western China nickel mine has historically been difficult due to the presence of large amounts of serpentine minerals (Feng, et al., 2012). Many studies reported that serpentine minerals tend to have a positive potential at pH values up to 9.5, while sulphides (such as pentlandite and chalcopyrite) have a low isoelectric point(Feng, et al., 2012). Serpentine minerals can form surface coatings on negatively charged sulphides surface due to electrostatic attraction when they interact with each other, which may also reduce collector adsorption and increase the hydrophilicity of the sulphide particles. In order to improve the flotation of nickel sulphides, sodium hexametaphosphate, sodium silicate, carboxymethyl cellulose (CMC), and other agents are used to disperse serpentine coating from sulphide surfaces in the flotation of the Jinchuan deposit and other nickel ores in China ( Kirjavainen and Heiskanen, 2007; Lu, et al., 2011). However, it is difficult to improve of the sulphide flotation due to the high dosage and the lack of selectivity."

Jan 1, 2018

By Robert M. Vadas

Special considerations are described as they apply to the design of ring gears for high-power grinding mills. AGMA requirements, the importance of the supporting structure, material selection and related field experience are discussed, with special emphasis on available and developing manufacturing technologies.

Jan 1, 1978

By David Estrella, Hector M. Lizama, Jhonny Carrión

"Microcel™ sparging systems were installed on one column of the molybdenum cleaner circuit and one column of the copper first cleaner circuit at Antamina. The Microcel™ system is known to generate finer bubbles than jetting-type spargers, and smaller bubbles have been associated with higher recoveries in flotation. Alternating tests were carried out on the molybdenum column, using either jetting-type spargers or the Microcel™ system. Experimental conditions of gas flow rate, wash water rate, and froth depth were tested. Use of Microcel™ decreased the bubble sizes from 2.6-2.9 mm to 1.5-2.0 mm. In addition, Microcel™ improved both unit molybdenum recovery and unit molybdenum concentrate grade. In the copper first cleaner circuit, side by side tests were carried out that compared the Microcel™ column with a parallel columns fitted with jetting-type spargers. Best results were obtained at manifold pressures of 260-290 kPa, where bubble sizes of 1.6-2.6 mm were observed. In either copper or molybdenum flotation, the Microcel™ system required only 50-60% of the gas flow used by jetting-type spargers.INTRODUCTIONAntamina is a copper-zinc mine located in the Peruvian Andes. Compañía Minera Antamina is owned by BHP Billiton (33.75%), Xstrata (33.75%), Teck Cominco (22.5%), and Mitsubishi (10%). The mine was commissioned in 2001 with a capital investment of US$2.3 billion, and has a nominal 100,000 t/d mill capacity. Mining, milling, flotation, and tailings impoundment take place at the mine site, which sits at an altitude of 4,300 m above sea level. The deposit is a polymetallic skarn ore body with intrusive phases of quartz-monzonite porphyry into Cretaceous aged limestone [Evans et al, 2005]. Ore body thickness is 100 to 150 m and has the shape of a flat-lying crescent. Copper is present mainly as chalcopyrite with a minor bornite component. Zinc is present as sphalerite. Molybdenum is present as molybdenite. Some lead, bismuth, and silver are associated with the sulphides. The deposit is currently classified into six main ore types [Dechert, 2006], grouped into two categories: copper and copper-zinc. The mill produces four concentrate types: copper, molybdenum, zinc, and lead-bismuth. Copper, zinc, and lead-bismuth concentrates are transported by pipeline down to the port of Huarmey. Molybdenum concentrates are bagged and trucked to port."

Jan 1, 2008

By Eric Schaub

Hot Blast Stove Systems are an important equipment of a Blast Furnace plant. During the last years, performance requirements and operation practice for the Hot Blast Systems have changed and have a big influence on the Blast Furnace operation. Therefore it is necessary to keep the Hot Blast System in proper condition in order to maintain the production capacity of the Blast Furnace. It is important for operators to know the condition and relevant constrains of a Hot Blast Stove Plant. Assessing its condition on a regular basis, especially in advance of a Blast Furnace relining is therefore advisable. Considering the individual condition of the Hot Blast Stove Plant, improvements in operation, but also specific and dedicated repairs might be implemented. Design improvements can be implemented as well during such repairs. This paper will describe some of these design improvements, will illustrate their implementation in new hot blast stoves but will also describe repair methods for existing stoves. In addition new developments became popular during the last decade, like the so called Dome Combustion Stoves, which was invented already 30 years ago in Western Europe. Paul Wurth’s development in this regard will be discussed in this paper as well.

Oct 30, 2017

By D Hope, D K. Mukhopadhyay, J D. Harvey

South32 (S32), a globally diversified mining and metals company, is listed on securities exchanges around the world (ASX, JSE, LSE), with its primary listing being on the Australian Securities Exchange (ASX). Chapter 5 of the ASX Listing Rules (Australian Securities Exchange (ASX), 2019b) requires a mining entity to provide a summary of governance arrangements and internal controls with respect to its estimation processes, estimates and reporting of Mineral Resources and Ore Reserves annually. As a global company, it is also important to design and implement all governance processes and internal controls which can be used consistently across the organisation. The three lines model (previously known as the ‘three lines of defense’ model) is employed across South32 to manage risk where the first line (Practitioners) designs, implements and executes processes and controls to manage risk; the second line (Stewardship) identifies material gaps and improvement opportunities in the first line by monitoring conformance with the group requirements, legislative and regulatory obligations. Second line also assists with the development and improvement of core fundamentals based on industry good practise. The third line (Group Assurance) provides independent and objective assurance over the Group’s system of risk management and control. The estimation of resources and reserves for most of the operations within South32 is managed by the Planning function. The estimation process is part of the annual Life of Operation Plan (LoOP). The LoOP identifies and assesses the strategic alternatives for the development of an operation and recommends the preferred pathway based on value and risk. The LoOP starts with opportunity framing and the updated resources as an input and ends with the short-term plan and annual budget (the outputs). Ore Reserves estimates are one of the outputs from the LoOP. All the inputs and outputs follow internal standards and procedures which includes peer review and performance reconciliation. Stewardship (Second line) which is a centralised function has standards in place to ensure compliance to internal controls and external regulatory requirements. This includes assessment of the competence of Competent Persons, technical reviews, independent audits and training in the relevant chapters of the ASX Listing Rules, Guidance Notes and Appendices. Group Assurance (Third line) which reports to the Risk and Audit Committee of the Board of Directors ensures the design and operating effectiveness of the processes, standards and procedures associated with the estimation and reporting of resources and reserves. While the level of scrutiny has a different intent for each line in the three lines model, the overall purpose is to achieve a consistent outcome across the organisation

May 24, 2023

By Li Ma, Shaoguo Chen, Gele Qing, Qihang Liu, Keng Wu

Olivine contains higher MgO element, which can be added into blast furnace burden to improve slag stability and fluidity. Effect of calcined olivine and untreated olivine on low silicon pellet production process and quality was studied in this paper. The results shows, calcined olivine has no effect on bursting temperature of green pellet, however the bursting temperature of green pellet will decrease with increase of untreated olivine ratio. Untreated olivine has slight effect on green pellet strength than calcined olivine while the ratio is higher than 2%. The compressive strength of low silicon pellet will increase first and decrease afterwards with increases of calcined olivine ratio under firing temperature of 1250°C, whereas, the changing sequence is reverse fired under 1280°C. The result of untreated olivine pellet compressive strength is same as calcined olivine pellet. However, the compressive strength and metallurgical property of calcined olivine pellet is slightly higher than that of untreated olivine pellet under same condition.

Jan 1, 2015

By Gurubasayya Swamy

This paper presents the consequences of modernization and expansion of process plant by implementing SAG and Ball Mill and Carbon-in-pulp technology at the Hutti Gold Mine. From the inception of the process plant, it has undergone many changes for the improvement. In the beginning, only gravity recovery of gold was carried out by using Pebble Mills and Strake Tables. Later amalgamation, Cyanidation and Zinc precipitation and finally Carbon-in-pulp gold recovery system was implemented. Grinding plant was modernized by implementing SAG and Ball Mill and Knelson concentrator for free gold recovery as a result, the production rate, rate of recovery, reduced man power, Modernization and expansion of process plant has also yielded in safe and smooth running of the plant. Keywords: sag and ball mill, cip, modernization and expansion, productivity, gold recovery

Sep 1, 2012

By Joe L. Castagno, Kenneth H. Johnston

Several hundred membrane - filter tests were made as part of a program to develop equipment and procedures to evaluate the quality of waters and to determine the quality of water suitable to efficiently flood oil sands of known permeability . Results indicated that neither the color of the water nor that of the precipitate on a membrane filter is a criterion for determining the quality of injection water . Reasons for poor water quality include poor operation of filtering systems , dirty filtering aggregates , excessive amounts of oil in injection water , commingling of incompatible waters , and excessive use of chemicals . A good water is required to efficiently flood sands of low permeability , but fair results may be obtained in flooding more permeable sands with poorer quality water .

Jan 1, 1964

By V. A. Chanturiya

There is an obvious disproportion in Russia gold-mining industry between the structure of gold reserves and the gold-mining techniques. The bulk of gold (over 70%) is extracted from alluvial deposit, 20%~25% from bedrock occurrences and 5%~7% from complex copper-zinc and polymetallic ores. The proved gold-bearing reserves are distributed as follows: alluvial ?19%, bedrock ?80%, the latter being sufficient to supply gold at the current production level for 100 years to come. In Russia, like elsewhere in the world, development of primary gold deposits is considered a first-priority line of development for gold-mining industry. Most of the gold-containing ores characteristic of Russian gold deposits are resistant ores with gold content varying between 3 ppm and 5 ppm usually showing quite low gold and silver recovery by cyanidation. Processing resistance of gold-containing mineral complexes is related to the presence of gold particles of submicrometric (<1.0 µm) and nanometric (10~100 nm) size, mostly asso-ciated with pyrite and arsenopyrite. Therefore switching over to processing bedrock entails a num-ber of technological problems that stem from chemical and physical resistivity of ores. The chemical resistivity can be overcome through flotation, oxidation roasting, autoclave leaching (biohydro-metallurgical oxidation), etc. The physical resistivity can be dealt with by resorting to traditional power-intensive methods,e.g. grinding to a ?40µm size, thermal treatments of sulphide concentrates and non-traditional high-energy methods of liberating the sulphides by means of power attack, e.g. electro-chemical oxidation, exposure to electron beam radiation and other methods. The modern non-traditional processes for treatment of rebellious noble metal-bearing ore, aimed at improving disintegration efficiency for finely dispersed mineral complexes are analysed. Advantages and perspectives of a new high-efficient, energy-saving and ecologically safe process of the nanosecond high-power electromagnetic pulses (HPEMP) effect are proved. The said process provides a stable increase in the valuable component recovery at lower energy consumption and production costs of the finite product at the stage of dressing rebellious gold-bearing ores and concentrated products. The experimental data prove high efficiency of the preliminary impulse treatment, thus, the increase in the gold recovery at the cyanidation stage amounted to 4%~12% from rebel-lious ores, 10%~30% from gravity concentrates, 5%~45% from flotation concentrates, 30%~80% from oil flotation tailings.

Jan 1, 2014

By Tapas Kumar Mukherjee, Sujit Kumar, Sanjay Kumar Singh

This paper dwells on the epic blast conducted at Tata Steel’s captive coal mine in India and the insights drawn from it. Optimal blast design parameters had to be ascertained for operating benches (6.56 yards (6 meters) to 16.40 yards (15 meters)) where shovels and mining pay-loaders are deployed. Better fragmentation and suitable muck profile with controlled vibration levels were the pre-requisites. The landmark blast was carried out at Quarry-AB, West Bokaro on 17th March 2017. The colossal blast was done with 275 US ton (250 tonnes) of explosives poured down 1074 drill holes of 6.5 inch (165 mm) diameter. This blast is unique from the perspective of vibration control as it was conducted near local villages situated beyond 546 yards (500 meters) but within 601 yards (550 meters)) from the blast site. The entire array of preparatory activities had been successfully and impeccably executed within the same day. The optimization was achieved through meticulous coordination between TSL team, M/s Solar and M/s IEL. When a rock is blasted, numerous interactions occur among granular particles which are impacted by rock mass properties, explosives properties, blasting geometry and the detonation timings. Optimized use of resources requires a better understanding of these interactions. Extensive field studies have shown that blast fragmentation and suitable muck profile influences the performance of downstream processes in a mine. Consequently, profitability of whole mining operation can be greatly improved through optimized fragmentation. For arriving at the best blast geometry, several blasts were conducted with differing ‘burden and spacing’ design and charging pattern at various loading benches of the mine. Eventually, the largest ever blast was successfully carried out. This accomplishment is the culmination of the insights derived, confidence built, and expertise evolved through a progression of larger blasts conducted earlier (202 US tons (184 tonnes) and 143 US tons (130 tonnes) respectively) by the same team. All blast parameters were within the recommended level and no adverse impact on nearby structures was evidenced. In-the hole VOD of different explosives was determined and placement of boosters was standardized. The signature blasts were conducted to optimize the delay interval between the holes in a row and between the rows. Blasting parameters were fine-tuned in alignment with the desired fragmentation level and muck pile profile conducive to smooth and expeditious loading and hauling by mining HEMM. Rock fragmentation analyses were carried out using photo-analysis system. The insights gained from this blast would serve as the cynosure for planning and carrying out more such blasts with highly optimized parameters in the future with the intent of improving mining efficiency and productivity

Jan 1, 2019

By C. Morel, P. Fredes, L. Rojas

This article presents a comprehensive study on the development and application of the specific module called "Exclusion Zone" created by Orica to determine blast evacuation exclusion zones. This module, integrated into the "SHOTPlus™ (blast design software)" software, has been used in the context of optimizing equipment evacuation exclusion zones in a northern Chile mine. The main objective has been to reduce the travel times of extraction equipment without compromising the safety of individuals. The module considers various factors such as the explosive charges used, stemming, sector topography, and detonation sequence to determine the rock projection generated by the blast. Furthermore, it utilizes information collected by drones and support tools such as Groundprobe and BlastVision™. The results obtained demonstrate that the use of this technology has allowed the optimization of blast evacuation distances in the northern Chile mine, generating significant economic benefits for the client.

Jan 1, 2024

By L Dzinza, K C. Corin, M Tadie

The recycling of process water comes with increased electrolyte concentrations that affect water quality, which may in turn affect the flotation performance of valuable minerals (Hirajima et al, 2016). Electrolytes such as Ca2+, SO4 2- , Mg2+ and S2O3 2- have been surmised to have an impact on the action of flotation reagents such as collectors (Ikumapayi et al, 2012). Xanthate collectors are known to play a significant role in imparting hydrophobicity on mineral surfaces to enhance their flotation. The interaction between minerals and xanthates is well known to be electrochemical in nature. Such redox processes may be elucidated by electrochemical techniques. Since the mechanisms involving the interactions between electrolytes in process water with sulfide minerals and the subsequent adsorption kinetics of collectors are not well understood, this study therefore aims to provide fundamental knowledge to unpack the mechanisms involved when electrolytes interact with Platinum Group Minerals (PGMs) and how these interactions may affect xanthate adsorption. The interaction of sodium iso-butyl xanthate (SIBX) in the presence of electrolytes at increasing ionic strength was investigated by rest potential measurements, to explain the impact of electrolytes on the adsorption of SIBX on PGMs in the flotation process. Rest potential measurements for PdTe2 and PdS were conducted in an air saturated 0.05 M di-sodium tetraborate decahydrate solution, in the absence and presence of SIBX and electrolytes. It was found that the existence of sulfide and telluride on palladium affects the mechanisms in which electrolytes interact with Pd mineral surfaces. An increase in the ionic strength of Na2S2O3, CaCl2 and MgCl2, increased the interaction between the salts and PdS, thus decreasing the extent to which SIBX interacted with PdS. An increase in ionic strength for Na2S2O3 increased the interaction between Na2S2O3 and PdTe2 and therefore decreased the extent to which SIBX interacted with PdTe2. Other salts investigated in this study increased the rate of oxidation of PdTe2 with an increase in ionic strength thereby enhancing the interaction of SIBX and PdTe2. This study has shown that mineral type, electrolyte type and concentration all have an impact on the mechanisms that result in the adsorption of SIBX on PGMs.

Aug 24, 2022

By David L. Brostrom, William C. Brice, Perry A. Canton

The business of mineral exploration and development has become much more than simply a problem of locating orebodies and designing mines. Favorable economic analysis of mining and processing feasibility is no longer sufficient to justify the development of a mine. New laws, enacted by virtually every level of government, require comprehensive land use planning, environmental analysis, mineland reclamation, mine safety studies, and many other considerations. This profusion of new laws says in effect, that the mining company is no longer responsible only to its stockholders. Mineral development today can be compared to a partnership. As in all partnerships, the risks and liabilities as well as the benefits are held jointly by all the participants. In addition to the mining operator, this partnership consists of the public, through its many levels of government, interest groups, and individual citizens. Therefore, you&apos;d better know your partner very well - his responsibilities and capabilities. Mining is considered a high risk venture. The risk on the part of the operator and the lending institutions has long been recognized. The risk that the public and its government take in these mining ventures has now been recognized also. The people and their government have learned that they inherit, through abandonment or forfeiture, the mistakes and problems of individuals and companies regarding these natural resources. In looking through the "Mining Engineering Handbook" recently published by the Society of Mining Engineers, I noted that in their discussion of liability for excavations, the authors quoted from the book of Exodus, 20th chap., where Moses said to his people: "When a man leaves a pit open, or when a man digs a pit and does not cover it, and an ox or an ass falls into it, the owner of the pit shall make it good; he shall give money to its owner, and the dead beast

Jan 1, 1974

By Deepak Malhotra

This paper discusses the need for periodic auditing of mineral processing flowsheets and the potential benefits a company can gain from a study of this nature. A carefully designed flowsheet auditing can have a significant impact on the metallurgical performance in the plant. Several case studies illustrating the potential benefits that can be attained from flowsheet auditing of mineral processing plants are discussed.

Jan 1, 1986

By M. Dupuis

Recently, a new approach to controlling alumina feeding in a H.H. cell has been proposed [1, 2 and 3]. This approach, labeled In Situ aluminium cell control, is based on a correlation between the slope of the cell voltage during a no feed observation period and the dissolved alumina concentration in the bath. Once the dissolved alumina concentration has been estimated, a primary calibration surface uniquely relating the dissolved alumina concentration and the anode-cathode-distance (ACD) to the cell voltage is used to estimate the cell ACD. Once both the alumina concentration and the ACD have been estimated at the end of the observation period, a PID controller can be used to regulate the rate of alumina feeding using only the normalized cell voltage to calculate the error between the estimated dissolved alumina concentration and a target value. The In Situ aluminium cell control algorithm has now been tested with the Dyna/Marc [4, 5 and 6] cell simulator demonstrating that it should be possible to control a H.H. cell in this manner with less variation in the dissolved alumina concentration and other process variables producing a prediction of improved cell current efficiency and power efficiency.

Jan 1, 2011

By Witold J. S. Ostrowski

Stabilization of water-bearing sediments by the freezing method for shaft sinking has been used for over 80 years on the European Continent. The real application of this method in Canada started with the development of the potash mines in Saskatchewan during the past fifteen years. The great depth to which it is applied creates a number of problems which have to be seriously considered by engineers in order to produce a safe and economical design. Freezing depth, thickness of the ice wall, number of the freeze holes, capacity of the freezing plant, pre-freezing time, etc., are the most important points which have to be established. Recent field experience in freezing to great depth in the Saskatchewan area is immensely interesting and important for further development of our potash mining and the application of the freezing method.

Jan 1, 1967

By W. V. Liu, D. Omane, H. Yu, Y. Pourrahimian

"A large-scale wildfire had broken out at Fort McMurray in Alberta, Canada during May 2016. Many oil sands mining activities were affected due to the wildfire and the associated ash emissions. In particular, ash emission generated from the fire outbreak is a huge problem during the post-fire cleanup. These emissions pose a severe health hazard to workers, environment, and global climate. The ashes emitted into the atmosphere are caused by either human activities or climate conditions. The objective of this research is to assess the effect of three different ash dust suppressants, namely water, #1 surfactants, and #2 polymers at various volumetric concentrations on ashes samples to prevent propagation of fine solid emissions into the atmosphere. It is found that both #1 surfactants solution and #2 polymers solution are effective in retaining fugitive ash dust generated from the ashes. Volumetric concentration efficiency of 0.05% of #1 surfactant and 5% of #2 polymers in 500 ml of water have been proven to provide ash dust retention efficiency greater than 99% after the spraying of these suppressants. It is also found that both #1 surfactants solution and #2 polymers solution maintain an ash dust retention efficiency higher than that of the use of only water. This confirms the merit of using chemical dust suppressants on fugitive ash dust for a longer period, which is proven by the 72-hour data from this experiment. This study gives a general view of how effective chemical suppressants on fugitive ash emissions work. INTRODUCTION On May 1st, 2016, a large-scale wildfire gutted Fort McMurray, Alberta, Canada. Many oil sands mining activities were affected due to the wildfire and the associated ash emission. Due to the wildfire, some of the biggest oil sands companies in Fort McMurray such as Royal Dutch Shell and Suncor Energy shut down their oil production, at 255,000 and 350,000 barrels per day respectively [1]. Syncrude Canada Ltd scaled down its normal production capacity level of 350,000 barrels per day [1]. This generated an estimated loss of about 1.1 million barrels of oil production per day, constituting a 30% reduction in the Canadian daily oil production, crippling the economy [2]. This loss in production by the companies translated into 0.33 % of the Alberta GDP in 2016 constituting a loss of $985 million and 0.06 % of the entire Canadian economy [3]. In 2017, it is estimated that the rebuilding and reclamation of the affected areas in Fort McMurray will add $ 1.3 billion in GDP to Alberta’s economy [3]. A population of over 90,000 people was evacuated from the location and its surroundings for health and safety reasons [4]. The fire destroyed about 2,400 structures and over 500,000 hectares of forest vegetation in Fort McMurray, leaving an estimated 232,000 tonne of post-fire ashes [5,6]."

Jan 1, 2017

By W. F. McDermott

One of the major improvements in ore grinding economics in North America has been the introduction of autogenous grinding. The history of this has been well documented in previous AIME presentations and in the literature. Pickands Mather & Co. has been very active in the development of autogenous grinding since 1957. This early work led to the application of autogenous grinding to the Wabush Mines ore in 1965, with the installation of 6-24 ft. diameter by 8 ft. long - 1,750 HP mills. Development work recently completed in 1971 on another ore has led to the decision to install 5-36 ft. diameter by 15 ft. long - 12,000 HP mills when this project goes ahead. Between these two decisions lies a tremendous amount of research, development, and application of autogenous grinding to a variety of ores. The Pickands Mather Metallurgical and Research Laboratory in Hibbing, Minnesota has tested, in its pilot plant facility, ores from 9 different deposits. Some of these deposits have as much difference within their own ore types as there is between the various deposits. Therefore, it is safe to say that over 20 different ore types have been tested and flowsheets developed for commercial applications. Of the 9 projects, 3 are in operation. These are Wabush Mines in Labrador, Canada, (1) Savage River Mines in Tasmania, (2) and The Griffith Mine in Red Lake, Ontario, Canada. (3) Pilot plant work has encompassed over 300 individual tests. These tests were carried out in mills that were 5-1/2, 8, and 12 ft. in diameter. Grinding power requirements for the primary autogenous milling has varied from 2 to 30 KWH/Lt of crude ore.

Jan 1, 1972

By Andre L. De Vegt

For the past eight years Paques has been engaged in the development and installation of treatment systems based on biotechnological processes to remove sulfur compounds from water, air and gaseous streams. Metal and sulfate can be removed from mine waters using two biological steps: 1. Sulfate reducing bacteria convert sulfate to hydrogen sulfide (HzS). The HzS reacts with the dissolved metals to form insoluble metal sulfide precipitates. 2. Sulfide oxidizing bacteria convert excess H2S to elemental sulfur. Paques has designed and installed a groundwater treatment system for the Budelco zinc refinery in the Netherlands to remove metals and sulfate as described above. The system has been operating since May 1992 treating a flow of 5000 m3/d. A test program, utilizing a large scale pilot plant, will commence in November 1995 at a copper mine in the U.S.A. to remediate groundwater contaminated with sulfate and heavy metals. Biological reactor performance and selective metal recovery will be studied. Sulfur dioxide (S00 can be removed from fluegas using a combination of scrubber technology and the two biological steps. The end product is elemental sulfur. A commercial size biological desulfurization plant has been in operation since July 1994 treating 50,000 Nm3/h of fluegas. Sulfide can be removed from mining waters or anaerobic wetlands using a THIOPAQ® Sulfide Oxidizing reactor.

Jan 1, 1996