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By A. J. Paul Laprairie

The process for which it is to be used is too often the only consideration in the design of a vessel. A de-sign allowing for practical manufacture and erection, as well as for proper maintenance, can often give over-all economies. Most platework in-stalled today is of welded construction. Therefore, metallurgical control is important in its manufacture. Also, because many concentrating and re-fining processes tend to be corrosive, the subject of protective coatings as a part of the manufacturing process is extremely important. The plant de-signer should know how to evaluate and specify controls for the metallurgy and for the coatings. Mining operations are becoming more sophisticated in the field of mechanical engineering. More and more emphasis is being given to preventive maintenance. The first step in any maintenance program, however, is good inspection service. This paper will suggest methods for the inspection of platework, and outline methods for repair and replacement.

Jan 1, 1963

By A Falter

Gyroscopic surveying instruments, which apply the physical law of a gyroscope, are being used for deter-mining the azimuth of lines with a high degree of ac-curacy. In the past ten years, gyro-theodolites have been introduced widely for underground orientation in the mining industry of Russia, Germany and South Africa. Gyroscorpic methods eliminate awkward procedures of conventional shaft plumbing, and provide more safety, excellent control and the highest precision at any point under-ground without interference with hoisting operations. The advantages of gyroscopic orientation in geodetic surveys become obvious in primary and secondary triangulation, in the determination of co-ordinates of single triangulation points, using the method of trigonometric re-section and intersection, and when traversing over long distances or in areas with obstructed view. Other fields of application are found in geophysical surveys and in the orientation of technical objects; e.g. radar stations, relay stations and ballistic missiles.

Jan 1, 1964

By S. F. Guo, Z. F. Zhan, X. L. Huang, Y. Zou, S. W. Qi

"FLAC3D is an important numerical analysis software to study dynamic response of rock slope. In application of the program, the common issues such as absorbing boundary and the method to apply wave have been well studied. However, effects of model mesh size, damping and width of slope are still unknown. In order to make the result more convictive, this article has discussed the above issues systematically. It found that when the maximum mesh size is smaller than 1/10~1/8 of the smallest wavelength, the mesh size is smaller, the computational accuracy is higher. Meanwhile, values of damping and width of slope have no effect on the result. Additional, results of FLAC3D modeling on wave transmission across rock joints agree well with analytical solutions, so it has verified the capability and accuracy of FLAC3D on dynamic response of rock slope.INTRODUCTIONChina is a mountainous country accompanied with many earthquakes. Thousands of geological disasters are triggered by the Wenchuan Earthquake in Sichuan Province, and the majority of the disasters are landslides induced (Xu et al., 2009). Meanwhile, the paper (Li et al., 2003) points out five significant issues about dynamic loading in the area of geotechnical engineering, which includes the study of rock slope stability under earthquakes, and the dynamic response of rock slopes is one of its important study issues."

Jan 1, 2015

By Harold L. Gibson, David H. Watkinson

"Volcanogenic massive sulphide deposits of the Noranda Camp cur throughout the Noranda Shield Volcano but are concentrated and along the margins of the Noranda Cauldron. The deposits are realized along synvolcanic faults that also accommodated subsince and controlled the location of eruptive centres. Deposits within e 3 000 m thick Mine Sequence formed during a period of active volcanism and subsidence coinciding with the onset of two cauldron subsidence cycles. The Noranda Cauldron was a restricted site of 10malously high heat flow and structural permeability that favoured e development of a high-temperature hydrothermal system. Metals may have been derived from leaching of aquifer rocks by convecting a water or directly from a shallow underlying magma chamber, now presented by the Plavrian Pluton, that was at its highest position !thin the crust during cauldron subsidence. The deposits formed rough a combination of sulphide precipitation from exhaled fluid td replacement at and below the seafloor in a manner analogous to ose on the modern seafloor.RESUMESi les dépôts de sulfures massifs volcano gènes du camp minier de ~uyn-Noranda sont présents dans les différentes parties du volcanluclier de Noranda, ils se trouvent concentres toutefois, en plus ·and nombre, sur le pourtour de la caldeira (cauldron) de Noranda. ~s dépôts sont localises le long des failles synvolcaniques qui ont cilite la subsidence et contrôle la position des centres d’éruption.~dépôts situes dans la séquence des mines (3 000 m d’épaisseur) sont formes durant un épisode d' activité volcanique et de subsiden qui coïncide avec l' amorce de deux cycles d' affaissement de la rldera (cauldron) de Noranda. Celle-ci Jut le site exclusif d’unflux : chaleur anormalement élevé et d’une perméabilité d’origine cucturale qui ont favorise le développement d’un système hydrothermal a haute température. Les métaux proviennent soit directement d’une chambre magmatique situee afaible profondeur, so it d’un lessivage des roches de l’aquifère par l’eau de mer circulant par convection. Cette chambre magmatique, représentée maintenant par le pluton de Flavrian, se trouvait à son niveau le plus élevé dans la croute au moment de l’affaissement de la caldeira (cauldron). Les dépôts se sont constitués par un mecanisme combinant remplacement et précipitation de sulfures à partir des fluides exhalatifs, au niveau ou au-dessous du plancher océanique, de la même manière que se forment de nos jours, les dépôts de sulfures massifs au fond des océans."

Jan 1, 1990

By P. Groleau, O. Tavchandjian, D. Marcotte

In open pit mining, each small mining unit (SMU) is selected for mill processing based on an estimate of its true grade. The estimation is usually done using analyses of cuttings from blast holes within that SMU. One common estimator used for selection is the arithmetic average of within-SMU samples. This estimator is conditionally biased. The effect of a conditional bias is to overestimate the profit really recovered from the deposit. For this reason, a conditionally unbiased estimator is preferable. Increasing the number of samples generally improves the accuracy of the estimation (and diminishes the conditional bias, if present, of most estimators). However, there exists a practical limit where an additional sample does not improve the estimation sufficiently to cover the expense of making the analysis. This limit is specific to each deposit and depends on geostatistical parameters, economic factors, and mining parameters. This study examines how the number of samples affects the recovered reserves and the resulting profit. Also, the effects on optimal profit of varying the different factors are examined. Globally, the number of samples required increases with the selectivity of the operation. For a given ore deposit, the greater the number of SMUs selected for processing, the fewer samples are required and vice-versa.

Jan 1, 1998

By Darren Medd

Kumtor Gold Company (KGC) currently operates the 500,000 tonnes per day Kumtor open pit gold mine located in the Issyk-Kul region of the Kyrgyz Republic at an elevation of more than 4,000 m. To supplement the open-pit mill feed with high grade underground ore from outside the current pit limits, KGC started pre-production design and development of the underground mine for the SB ore zone in late 2006. The initial phase of pre-production development consists of exploration and haulage declines which, upon completion, will provide ventilation and access to the underground mine. Design and construction of these declines presented many challenges to the project team considering the mines unique location at high altitude, the limited experience with Western underground mining techniques in the Kyrgyz Republic, and the impact of the nearby Davydov glacier and resultant ground conditions. Completion of the exploration and haulage declines was undertaken jointly by KGC and mine contractor, J.S. Redpath Limited (Redpath). The initial phase of development including several ground falls provided detailed information on geotechnical ground types and conditions that were useful in determining the overall mine design and methodology for production. This paper covers the various aspects of the design and construction process of developing the declines under the glacier, minimizing the likelihood of further ground falls, and the journey of both KGC and Redpath which led to the successful breakthrough between the declines on 01 July 2012.

Aug 1, 2013

By A. Luckita, A. Samtani, R. Barus, J. R. Donald, J. Syarifuddin

In conventional Rotary Kiln-Electric Furnace (RK-EF) laterite nickel processing, management of dust continues to be problematic. A more efficient processing of dust represents an opportunity for energy efficiency, increased production, and productivity. PT International Nickel Indonesia (PTI), together with Vale Base Metals Technology Development (VBMTD), has successfully developed and implemented a novel flowsheet enhancement that capitalizes on these opportunities. In the novel flowsheet, the dust recycle stream is moved forward in the RK-EF laterite nickel smelting process. The dust is injected into the kiln's main burner, as opposed to being recycled to the dryers. A similar treatment of dust is commonly practiced in the cement industry; however, application to nickel smelters has not been fully developed to date. This paper describes this dust insufflation technology, the process through which it was developed for laterite nickel processing, and summarizes the lessons learned. A key conclusion is that successful new technology development requires a multi-disciplinary team involving members from research and development, study management, engineering consulting firms, project implementation management, process technology and operations.

Jan 1, 2011

By A. L. Nunes, J. R. E. Garcia, G. Silva, U. Prasad, C. Rabe

"Drilling through the Guayabal shales, a gray calcareous shale, and the C1 to C100 formations, a well-cemented calcareous-sandstone in Corralillo field, Mexico, is a challenge due to severe wellbore instability problems. Additionally, there has been a history of ineffective reservoir stimulations by hydraulic fracturing. To predict and mitigate these subsurface issues, it is essential to characterize the mechanical properties and rocks strength for a better prediction of borehole stresses and collapse pressure during drilling. Various correlations can be used to estimate and/or determine the unconfined compressive strength but most of them are based on transit time and porosity.In this study, grain size distribution was combined with acoustic travel time, porosity and static Young’s modulus to develop a rock strength prediction model for the turbiditic sandstones of the Chicontepec basin. The main reason this combination of parameters was employed was because of the wide variations in rock strength estimated using traditional porosity-based correlations such as the McNally’s (1987), GMI-Jizba-E’s and Bradford’s (Bradford et al., 1987).To develop a new correlation, a geomechanical and microstructural campaign was initiated. Mineralogy by X-ray diffraction, pore and grain sizes by petrography, clay distribution by SEM and porosity by mercury intrusion porosimetry were measured. Static and dynamic Young’s moduli and Poisson’s ratios were acquired by triaxial and ultrasonic measurements on undisturbed sandstone samples from the Chicontepec basin. More than ten offset wells with wireline data, including transit time, porosity, density, resistivity and gamma ray, were used for reservoir and geomechanical characterizations.Our analyses lead us to propose a new correlation for predicting the uniaxial compressive strength (UCS) of sandstones of the Chicontepec Basin as a function of transit time and grain diameter, both of which can be derived independently from destructive laboratory tests. Our results also highlight the importance and value adding of a combined approach incorporating grain size analysis in the rock strength prediction. The UCS predicted using the transit-time and grain-size-based model presents a median value (P50) of 76 MPa, P10 of 55 MPa and P90 of 89 MPa."

Jan 1, 2015

By Chris Rule

This paper tells the story of the rapid commercial application of stirred milling technology at Anglo American Platinum?s many Concentrators. The first stirred mill ? a 10 000 litre IsaMillTM; the largest at the time, was commissioned in late 2003. The project development work was presented at SAG 2001. This operation was ?proof of concept? and vindicated the decision to scale up the technology; allowing a rapid and extensive roll-out of mainstream regrind mills as well as several further flotation concentrate regrind mills, over the next six years. Currently 23 stirred mills are in operation with 64 MW of installed drive capacity ? this paper describes the projects? roll-out and the significant results achieved to date. Many operational problems have been solved along the way, some of these will be described. The introduction of the technology has seen a step change in metallurgical results and progressively decreasing operating costs.

Jan 1, 2012

By D. Yuan, L. Yan, R. Kalanchey, M. J. Collins, I. M. Masters

Pressure oxidation tests have been conducted by Sherritt for a refractory gold-silver project located in China. The feed contained 39 g/t Au and 970 g/t Ag; the major gold-bearing minerals were pyrite and arsenopyrite. Since the feed contained a significant amount of silver, which can be refractory to cyanide leaching after pressure oxidation due to the formation of argentojarosite, the test program included investigation of methods to enhance silver recovery. The "lime boil" process proved successful and was incorporated into the flowsheet. Gold extraction from the lime boil product solids was 95 to 98%; silver extraction was up to 94%.

Jan 1, 2011

By William E. Roscoe

"Mineral exploration properties are those on which an economically viable mineral deposit has not yet been discovered. Such properties are bought, sold, optioned and joint ventured on the basis of their perceived potential for the existence and discovery of a viable mineral deposit. The intrinsic value of an exploration property is therefore based on the exploration potential. One measure of the exploration potential is the amount that can be justified to spend on exploration for a viable deposit.The appraised value method uses a cost approach to value exploration properties. It is based on the premise that an exploration property is worth the meaningful past exploration expenditures plus warranted future costs to test remaining exploration potential. Results of past exploration work are analyzed in order to retain only those past expenditures that are productive in terms of identifying remaining potential. Warranted future costs comprise a reasonable exploration budget to test that potential.INTRODUCTIONThe purpose of this paper is to describe a cost approach to the valuation of mineral exploration properties and to provide some valuation examples. The particular cost approach described is the Appraised Value Method, which is best applied to mineral properties at the exploration stage.At present there are no comprehensive regulations or guidelines in Canada which specify what approaches and methods to use for the valuation of mineral properties. In this paper, the Appraised Value Method described is one method that the writer considers to be accepted industry practice for mineral properties at the exploration stage.Mineral properties are valued for a number of reasons, including mergers and acquisitions, non arm's length transactions, pricing of initial public offering of stock, support for property agreements, litigation, expropriation, and insurance claims."

Jan 1, 2003

By I. Vazaios, M. S. Diederichs, N. Vlachopoulos

"As rock engineering moves from continuum to more discontinuum approaches for modeling, the engineer must make decisions regarding the degree of complexity to simulate for a given application, balancing the level of structural detail within the rockmass model with computational cost and result accuracy. It is important to consider that model does not need to include all the existent fractures and that representative geometrical properties for a given rock mass volume can be defined including only major structural entities.Within this paper, the scale-dependency associated with the geometrical properties of fractured rock is investigated utilizing a Synthetic Rockmass (SRM) approach with a view to characterize such ground to aid in the design of geotechnical works. In terms of process, the concept of the Representative Elementary Volume (REV) is used to determine the equivalent structural properties of the rockmass in order to justify the applicability of far-field behaviour of such ground. A large size Discrete Fracture Network (DFN) measuring 60m x 60m x 60m has been generated using the structural data obtained from LiDAR scanning of the Brockville Tunnel, Ontario, Canada. A number of DFN samples of varying sizes are extracted from the master network, generated using MoFrac, in order to be used as a the basis of the structural analysis of the rockmass. Volumetric measurements for the density and the intensity of jointing are employed in order to approximate the geometrical REV for the networks.In this paper a complete methodology of how to generate a DFN from LiDAR data and its analysis in order to determine the size of a geometrical REV is demonstrated. For the specific rockmass found in the area of the Brockville Tunnel, a geometrical REV measuring 3.5m x 3.5m x 7m is established. The results are generally in good agreement with the in-situ observations."

Jan 1, 2015

By R. Khanna, K. Hyun Ko, A. J. Berkovich, J. Hook

"The co-pyrolysis of synthetic polymer polyethylene terephthalate (PET) and agricultural wastes (naturally occurring polymer-macadamia nut shell) was investigated in the temperature range 473K to 1273K using a horizontal furnace with an aim to understand their thermal degradation under isothermal conditions. In-depth characterization of pyrolysis residues was carried out using x-ray diffraction (XRD) and solid state nuclear magnetic resonance (NMR) for carbon structure, and through determination of the concentration of unpaired electrons using electron paramagnetic resonance (EPR). In previous studies, it has been found that PET thermally decomposes ~ 650K-700K, releasing (~80 wt % of initial weight) gaseous products due to random chain scission. In the case of macadamia nut shell, three types of byproduct can be obtained from pyrolysis: char, tar and gaseous products. In the co-pyrolysis of macadamia nut shell with PET in 50-50 wt% ratio, total product weight ratio could be modified with the addition of PET acting as a hydrogen source. This is because a recombination of thermal cracking products of cellulose could be suppressed by hydrogen from PET, which will later lead to an enhancement of tar formation. In addition, pyrolysis around 673K is sufficient for bond cleavage to occur in cellulose and lignin leading to the formation of negatively charged activated carbon with high surface area, providing bonding sites for volatiles evolving from PET. Therefore the co-pyrolysis may be able to enhance the product yield (tar/char/solid carbon residue) along with a reduction in the release of gaseous products. During the co-pyrolysis, temperature was found to have a significant influence on the kinetics of thermal degradation and solid residual by-products after co-pyrolysis.INTRODUCTIONPlastics are being used worldwide in a wide range of applications in the modern society; their usage has resulted in increasingly a massive waste problem. The production of most synthetic plastics requires hydrocarbons that are produced from petrochemicals derived from fossil oil and natural gas, a non-renewable source (Speight 2011). Currently, plastic manufacture utilizes ~4% of world oil and gas production, and it is expected to drive further increases in petroleum demand by 1-2% due to their large volume of manufacture (Hopewell, Dvorak et al. 2009). Landfilling and incineration of plastic waste are the two main routes to plastic waste management (Encinar and González 2008). In Australia, only 10% of waste plastics were recycled in 2006 (White and Hyde 2011). This means that large amount of fossil fuels from plastics has either been simply burned for energy recovery or buried in the ground. There is an urgent need for developing alternative avenues for recycling waste plastics. Our group at UNSW has carried out extensive research on the recycling of waste polymers as carbon resource in steelmaking including slag foaming and carbon dissolution from waste plastics into liquid steel at 1600°C; the effect of basic plastic characteristics such as chemical composition, structure, bonding network etc. was examined (Sahajwalla, Rahman et al. 2009)"

Jan 1, 2012

By A. Warczok

Chalcocite concentrate obtained by magnetic separation and flotation of Bessemer matte is processed in the Inca top blowing bottom stirring MK reactor into semi-blister copper. The semi-blister is then converted into blister copper in the multi-purpose vessels (MPV) by oxidation of iron, nickel and sulphur. High melting point NiO and Fe30 4 are formed inside the MPV s, which together with Cu20 and smaller amount of fayalite are the major constituents of the solid mush. The accumulation of solid mush and buildup requires periodic MPV cleaning by adding reductant and copper-nickel matte, a unique process called "washout". Various reductants and their combinations, such as pig-iron, 15%Si Ferro-silicon and 50%Si Ferro-silicon, have been used for the reduction of solid mush and buildup. The possibilities of using calcium carbide as a reductant and slagging flux were examined experimentally at the crucible scale. The rate of reduction of MPV buildup was determined by continuous measurement of CO and C02 contents in the offgas and the flowrate of argon carrier gas. The rate of the buildup reduction with calcium carbide was approximately five times faster than the rate of reduction with coke. Additionally, the formation of CaO results in the melting of reduced buildup and formation of a slag at 1300°C and higher temperatures. It was found that simultaneous silica addition enhanced the melting and slag formation. The results showed the strong dependence of the reduction rate on temperature. Activation energy is approximately 225 kJ/mol. Expected benefits of using calcium carbide are related to cost saving on reductant, significant acceleration of solid mush reduction, and reduced amount iron input from reductant.

Jan 1, 2007

By D. Yu, T. A. Utigard, M. Barati

"Sulfation roasting of nickel concentrate to generate water-soluble metal sulfates was investigated as an alternative process to smelting for the recovery of valuable metals. The kinetics of dissolution of various species of the calcine in three leachants was studied; hot water, dilute HCl, and concentrated HCl. The results indicated that dissolution of sulfates by hot water at 90 ºC is achieved within 30 minutes. In order to increase the recovery of the valuable metals, acid leaching is necessary due to the existence of ferrite in the calcine.INTRODUCTIONInvestigations on the sulfation roasting of nickeliferous sulfide ores or concentrates were mainly carried out in 1950’s to 1990’s to generate water soluble non-ferrous metal sulfates followed by metal recovery by leaching (Stephens, 1953; Thornhill, 1954, 1961; Fletcher and Shelef, 1964a, 1964b; Fletcher and Hester, 1964; Frankiewicz, 1977; Norrgran, 1983). Commercialization of the sulfation roasting process was only performed by Falconbridge Ltd. (Thornhill, 1961; Boldt, 1967), which employed a sulfation roast process on nickeliferous pyrrhotite at 680 oC where Ni, Cu, and Co were leached and Fe2O3 was produced for the iron industry. In 1965, 118,342 tons of pyrrhotite was processed, however because of the huge SO2 emissions (no acid plant) relative to the nickel production and the poor economics, this plant was shut down.Nickel production from sulfide ores via pyrometallurgical means, especially the electric furnace smelting process, is a major emitter of SO2 to the environment and a big energy consumer (Warner, Diaz, Dalvi, Mackey, Tarasov and Jones, 2007). Nowadays, due to the more stringent environmental regulations as well as the need to reduce energy consumption, metal production by sulfation roasting is gaining more attention as an alternative process to smelting. The main focus of this paper is to investigate the extent and rate of leaching of valuable metals from the sulfation roasted nickel calcine, aiming to maximize the metal recovery and minimize the dissolution of iron species."

Jan 1, 2012

"This paper presents results of ongoing research being carried out at the University of New South Wales into improved methods for estimating rock mass strength. In this paper the rock mass strength of Hawkesbury Sandstone is assessed. An estimate is first made based on an extensive database of intact rock strength data being collated by the author and the assumption that the rock mass strength can be determined following the GSI approach. The resulting strength envelope is then compared with nine documented case studies where stress induced failure has occurred in tunnels excavated within Hawkesbury Sandstone. The case studies cover a range of conditions:• construction dates from 1880s to 2006• spans from 3.2 to 12.5 m• depths from 17 to 124 m• excavation methods of drill & blast, roadheader and TBM.Finite element modelling is used to assess the likely magnitudes of the stresses present at the time of failure. The finite element models are interrogated to provide the values of major and minor principal stresses in and around the mapped failure zone. Failure and stable points are then compared to the rock mass strength envelope(s) of Hawkesbury Sandstone derived using the Hoek-Brown criterion and spalling criteria. The Hoek-Brown rock mass strength envelope differentiates between the ‘failed’ and ‘stable’ zones remarkably well.INTRODUCTIONStress induced failures of rock masses are fortunately rare in civil tunnelling. However, when they occur they provide an opportunity to calibrate an assumed rock mass strength criterion. This paper compares an estimate of rock mass strength for the Hawkesbury Sandstone with the following cases where stress induced failure occurred in tunnels excavated within Hawkesbury Sandstone.• Cataract & Devines Tunnels of the Upper Canal (Upper Nepean Scheme)• Malabar Outfall Tunnel• Sydney liquefied petroleum gas (LPG) Storage Cavern• Northside Storage Tunnel• Cross City Tunnel• Lane Cove TunnelTwo-dimensional finite element modelling is used to assess the likely magnitudes of the stresses present at the time of the failures. The principal stresses are then compared to the assessed rock mass strength envelope(s) of Hawkesbury Sandstone derived using the 2002 Hoek-Brown criterion (Hoek et al., 2002) and the spalling criterion suggested by Diederichs (2007)."

Jan 1, 2015

By David G. Meadows

During the last decade Antofagasta Minerals? Los Pelambres Mine has dramatically increased its ore throughput following the fast initial phase ramp up through a series of planned incremental expansions. The original 85,000 mtpd, two SAG line plant was commissioned in 1999 and rapidly exceeded nameplate tonnage in only a few months. Following this, the inclusion of a pebble crushing circuit resulted in throughputs in excess of 114,000 mtpd and a recent, final third line SAG and ball mill addition have taken the plant to over 175,000 mtpd even with increasing ore hardness and changing ore feed characteristics. The progressive changes are described in this paper together with how the technical challenges have been met.

Jan 1, 2012

By Z. Jun, L. Kerning

Jinlong copper smelter and refinery, originally designed for 100,000tpa primary copper and started up in 1997, has been expanding its capacity on the basis of operational optimization and by modifying its facilities. Currently it is producing 210,000tpa primary copper, and the new phase of expansion project with a target capacity of 350,000tpa primary copper is ongoing. This paper reviews problems and improvements made with operation and equipment in the past years. Recent plant operation is briefly described. The expansion projects completed are summarized and the ongoing expansion project is present.

Jan 1, 2007

By C. J. Hartley

"Scandium oxide can be recovered as a by-product from process streams in a number of chemical and metallurgical plants including TiO2 sulphate pigment, Ni/Co laterite, zirconium oxychloride and uranium operations. The feed materials available for processing can be either mid or end of process streams containing many species in solution. This paper describes the strategies available to limit coextraction of elements into scandium containing streams from TiO2 pigment production and the removal of these elements to deliver high purity scandium oxide.A critical part of process development is to work within the constraints of the main process in terms of introducing new unit processes and producing minimal additional process intermediates and residues. This requires flexibility in designing flowsheets and plants to find novel process routes that avoid production of intermediates and/or the introduction of reagents that can compromise the main process operations.Bloom Energy has developed novel solvent extraction processes for the extraction and refining of scandium oxide that minimise impacts on core process streams within TiO2 pigment plants. The additional unit processes are designed to have minimal contact with pigment plant process streams to produce a concentrate that is refined to nominal 3N purity scandium oxide in a simple, small scale commercial plant."

Jan 1, 2016

By Jianwen Yang, Yucai Zhou, Yanhong Dong, Daixiong Chen

"The study of combined depressants for flotation separation of lead from copper has been carried out to solve the copper-lead separation problem. Test results show that the depressant of CMC (Carboxyl Methyl Cellulose) or sodium sulfite plays an important role on the selective depression of galena flotation. When the two reagents above are combined, the selective depression effect on galena is further enhanced. When the mass ratio of CMC to sodium sulfite is 1:4, galena was best depressed, with the lowest lead content in the copper concentrateClosed-circuit tests indicate that under a certain pH value of the slurry, with the best ratio of CMC to sodium sulfite as depressants, the copper concentrate with the grade of 28.23% copper and 4.12% lead is obtained, and the copper recovery is 84.87%; the lead concentrate with 68.12% lead and 0.86% copper is obtained, and the lead recovery reaches to 92.20%. An efficient separation of copper and lead is achieved with the combined depressants. INTRODUCTIONComplex copper-lead-zinc sulfide ore is abundant in China. With the rapid increase of mineral consumption, it has become one of the important sources to produce copper-lead-zinc metals. However, it is difficult to achieve effective separation of copper and lead, due to the complicated ore properties, such as fine dissemination, low copper grade, complex symbiotic relationship and similar floatability of copper and lead.Poisonous reagents of bichromate and cyanide are often used as depressants for copper lead separation. They have good separation efficiency, but pose serious pollution issues. As the environmental protection is becoming more and more important, it is a trend to replace traditional toxic reagents with new nontoxic efficient chemicals. Organic depressant FCLS studied by Liu has strong selectivity against galena, and does not depress chalcopyrite. A new type of galena depressant of CLS-01 discovered by Jin-lin Yang shows good results in the separation a mixed copper and lead concentrate. In addition, dextrin, chitosan and some other natural organic compounds (Drzymala, 2003; Huang, 2012; Qin, 2013) have also been studied to separate copper and lead."

Jan 1, 2016