Online monitoring of the interaction of balls and slurry with the Sensomag ®

Poster (2012, December 10)

Presentation of Optimag Project results. Optimag aims to optimize the ball milling operations through the use of an embarked sensor, called the Sensomag, and developed by Magotteaux to monitor in real ... [more ▼]

Presentation of Optimag Project results. Optimag aims to optimize the ball milling operations through the use of an embarked sensor, called the Sensomag, and developed by Magotteaux to monitor in real time the position of the slurry and the grinding balls. [less ▲]

Removal of phosphorous through roasting of oolitic iorn ore with alkaline earth additives

in Proceedings of the XXVI International Mineral Processing Congress (2012, September)

The present study is devoted to improvement of the leaching efficiency during phosphorous removal from high phosphorous gravity-magnetic concentrate. Before leaching the concentrate has been subjected to ... [more ▼]

The present study is devoted to improvement of the leaching efficiency during phosphorous removal from high phosphorous gravity-magnetic concentrate. Before leaching the concentrate has been subjected to roasting with the addition of either Ca(OH)2 or CaO. The oolitic iron ore is roasted at 900°C for one hour. This reflects in reaction between alkaline earth additive and quartz, aluminosilicates, phosphorus, and some other minor components of the gangue minerals. The application of leaching, physical separation, and wash out of salts has resulted in the decrease of phosphorus from 0.7 to 0.15 % and it is established that the major influencing factor is the concentration of acid and to a less extent duration of the leaching process. About two third of the phosphorus can be removed by roasting with 3 % CaO to hematite, coarse grinding to d50 0.3 mm, dry high intensity magnetic separation and leaching of the magnetic fraction with hydro-chloric or nitric acid. [less ▲]

Bio hydrometallurgical recovery of metals from Fine Shredder Residues

in Minerals Engineering (2011), Vol 24, Issue 11

The leaching step of an integrated hydrometallurgical process for the selective recovery of metals from polymetallic concentrates has been investigated. The concentrate has been produced by physical ... [more ▼]

The leaching step of an integrated hydrometallurgical process for the selective recovery of metals from polymetallic concentrates has been investigated. The concentrate has been produced by physical treatment of Fine Shredder Residues derived from a shredding plant processing a mixed feed. Bacterially assisted leaching experiments using a copper-adapted consortium of mesophilic bacterial strains have been carried out. Various technological parameters have been studied. Under optimal conditions about 95 % extraction levels for copper and zinc have been obtained. Bacterial presence has been found beneficial in view catalysing copper dissolution. [less ▲]

Impacts of grinding media alloys composition on the flotation of mixed oxides-sulphides copper ores.

Conference (2011)

While the influence of the grinding media alloy composition on the flotation performances of sulphide ores has been widely studied, its role in the flotation of mixed (oxide and sulphide) ores is poorly ... [more ▼]

While the influence of the grinding media alloy composition on the flotation performances of sulphide ores has been widely studied, its role in the flotation of mixed (oxide and sulphide) ores is poorly documented. For some deposits, the mixed ores zone is well developed and can be of great importance for the economics of a mining project. These ore types often present technical challenges for their beneficiation such as sulphides tarnishment, slimes generation, presence of hydrophobic gangue or presence of acid consuming gangue. This study highlights the importance of matching the right grinding media alloy to the mineralogy of the ore, particularly its degree of weathering and to the subsequent flotation scheme. Shifting the grinding media towards less electrochemically active alloys significantly enhanced the grade-recovery curves and the flotation kinetics of the sulphides fraction, particularly when high degrees of sulphides oxidation were induced within the orebody or during stockpiling. For ores with high acid consuming gangue and medium acid soluble copper content that require a preconcentration of the oxide fraction by flotation through activation by sulphidisation, the higher sulphides flotation rates achieved with the use of high chromium alloys limited the amount of sulphides entering the sulphidisation stages and led to a better selectivity between acid insoluble and acid soluble copper allowing better downstream extractive metallurgy performances. [less ▲]

Biosolubilization of copper from waste electric cables

in Harre, Jens (Ed.) Proceedings of the Copper 2010 International Conference (2010, June)

The paper reports on results from a laboratory tests for bacterial leaching of copper from scrap cables. The studied material is a reject fraction obtained after dismantling and separation of electric ... [more ▼]

The paper reports on results from a laboratory tests for bacterial leaching of copper from scrap cables. The studied material is a reject fraction obtained after dismantling and separation of electric cables during recycling of end-of-life vehicles (ELV). The copper has been met predominately in pure metallic form as tiny irregular shaped wires often coated with tin and well liberated from the plastic isolations. For bringing copper in solution, a bacterially assisted agitative leaching with mixed consortium of mesophylic microorganisms has been chosen. Continuous bacterial adaptation of the cultures to the substrate has been envisaged in order to provide an efficient way for ferrous iron regeneration during the leaching. It has been established that under optimal conditions of pH, density and temperature it is possible to recover nearly the total copper within short leach duration. The obtained pregnant leach solution could be subjected to subsequent copper recovery via solvent extraction, while the solid leached residue could be considered as non-metallic material containing plastics suitable for recycling. [less ▲]

Metallurgical performances of the sulphidisation route and the direct alkylhydroxamates flotation of mixed carbonated Cu-Au ores of the Kansanshi deposit

Conference (2009)

The roles of complexing agents in the sulfidisation and xanthate flotation of cobalt oxy hydroxides of copper-cobalt oxides ores from the Congolese Copperbelt

Conference (2006)

Complex mineralogy combined with a variable chemistry lead to various flotation responses of cobalt oxy-hydroxides present in oxidised and mixed copper-cobalt stratiform deposits of the Central African ... [more ▼]

Complex mineralogy combined with a variable chemistry lead to various flotation responses of cobalt oxy-hydroxides present in oxidised and mixed copper-cobalt stratiform deposits of the Central African Copperbelt. Optimum metallurgical results require very high dosages of reagents and the management of such high chemicals concentrations in the pulp at the plant scale is delicate. The transition period between high reducing conditions during the sulfidisation step and a more oxidising environment prevailing during collector adsorption is particularly critical. This paper demonstrates how the use of copper and cobalt complexing agents can significantly improve the process control and metallurgical performance. The different modes of action of these reagents are presented and mechanisms for the various reactions proposed. Plant results following the introduction of ammonium sulfate at the New Concentrator of Kipushi are discussed. [less ▲]

Ammonium sulphate as promoting agent of the sulphidization process of oxidized Cu-Co ores from the Luiswishi deposit (RDC)

Poster (2003)

The Luiswishi deposit belongs to the Cu-Co deposits of the Southern Group of the Katangian Copper Belt and is operated by a joint venture between EGMF (Entreprises Générales Malta Forrest) and Gecamines ... [more ▼]

The Luiswishi deposit belongs to the Cu-Co deposits of the Southern Group of the Katangian Copper Belt and is operated by a joint venture between EGMF (Entreprises Générales Malta Forrest) and Gecamines (Générale des Carrières et des Mines). The Cu-Co ore is beneficiated by the sulphidization process at the NCK (New Concentrator of Kipushi) at Kipushi. Sulphidization followed by flotation with sulphydryl collectors is a common practice for the treatment of oxidized base metals ores. This process is complex and its application at the industrial scale is quite sensitive. In Central Africa it is also a cost intensive treatment as the sulphidizing agent has to be imported. In order to improve the metallurgical performances and to optimise the economics of the process, a laboratory research program was carried out by the Laboratory of Metallurgy and Mineral Processing (MTM) of the University of Liège in close collaboration with EGMF and Gecamines. This program included the study of various flotation reagents as dispersing, depressing and activating agents. This paper presents the results obtained with the use of ammonium sulphate as activator of the sulphidized xanthate flotation. Although ammonium sulphate has been mentioned in the literature as a promoting agent of the sulphidized xanthate flotation of malachite, its effects on the flotation of cobalt oxides was not known. The testworks were carried out on various oxidized siliceous ore types from the Luiswishi deposit. A 1.7 l Agitair laboratory flotation cell was used. NaHS and potassium amylxanthate were respectively choosen as sulphidizer and collector. A mixture of gasoil and tall oil (90/10) was used as secondary collector. A multistage sulphidization was realised. Values of pH were followed during the different tests and an ion selective electrode Ag/Ag2S was used to control the Es potentiel evolution during the stepwise addition of the sulphidizer. The addition of ammonium suphate [(NH4)2SO4] simultaneously with NaHS led to the following results: -A marked improvement of the sulfidization kinetics leading to shorter conditioning times and limiting the number of sulphidizing stages required to reach maximum recoveries. -The inhibition of the depressive effect on Cu and Co flotation of an excess of hydrosulphide ions in the pulp. -An improvement of the selectivity of the flotation combined with higher cobalt recoveries. The promoting effect is indeed more effective for cobalt than for copper and cobalt recoveries were improved by 4 to 8 %. -A significant decrease of the sulfidizer consumption. These laboratory results were implemented at an industrial scale at the NCK at Kipushi. In close accordance with the laboratory results the sulphidization kinetics were improved and the cobalt recoveries rose by 7 % while maintaining the previous Cu and Co grades of the concentrate. Ammonium sulphate being a low cost and common reagent (it is easily found in the fertiliser industry or as a byproduct of the coke industry), its use significantly improved the economics of the flotation of Cu-Co oxides ores from the Luiswishi deposit. [less ▲]