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By Fiona Sofra, Briony C. Ruse, David B. Boger

"The sustainability of the mining industry must be addressed through improving tailings management. The use of thickened tailings and pastes stems from a paradigm shift towards designing tailings disposal sites to suit their surrounding environment, rather than manipulating the environment to accommodate the tailings. Thickened tailings and pastes usually exhibit non-Newtonian behaviour, so a thorough understanding of the rheological characteristics of the material is required in order to determine the disposal plant operating conditions.Full Cost Accounting techniques may be used to provide financial justification for the implementation of alternative tailings disposal techniques through the calculation of a disposal cost per tonne of tailings over the life of the facility. Improved disposal methods such as thickened tailings disposal involve additional initial capital expenditure but reduce environmental impacts. The cost savings associated with environmental impact mitigation are reflected in Full Cost Accounting outcomes.Rheological characterisation is significant as a design basis that may be analysed using Full Cost Accounting to justify the initial capital expenditure of dry disposal systems for improved environmental performance."

Jan 1, 2003

By L. Rintala

The design of a hydrometallurgical process starts with the analysis of the raw materials to be treated, for example mineralogy, chemistry, deposit size are analysed. Based on this information suitable unit processes for pre-treatment, leaching, solution purification and product recovery are selected. Typically, process design for the new ore deposit relies on laboratory tests such as pre-treatment and leaching experiments. The experimental work is the most time consuming and expensive part of the process design. Reducing the number of experiments would shorten the time of designing a new flowsheet or development of new process technology. A large amount of information is available about the hydrometallurgical experiments and the amount is increasing continuously. For example, word search using ?hydrometallurgy? from Scopus database results in over 4 000 publications with the word in title, abstract or keywords. This number consists of 2 500 articles, 900 conference papers, and 90 reviews since 1972. The number of hydrometallurgical publications per year has increased from 13 in 1972 to 150-200 in the last few years. The objective of this study was to analyze how detailed data of experiments about the gold extraction is published and how that data could be exploited more effectively when designing hydrometallurgical processing for new ore. The leading idea is that similar ores should have the similar response in leaching. If the published information was used more efficiently, the amount of experiments would be reduced. More than 200 cases of experimental data of gold leaching have been analyzed for this study. There are over 30 factors that could be used in comparison when selecting process alternatives, but challenging fact is that not all these factors are documented in all publications. Results show that the usefulness of the published data in the development of hydrometallurgical flow sheet for gold using decision-support tools is not that straightforward. The quality of the published information about gold extraction varied between the publications and the descriptions of the raw materials, experimental arrangements and results were often missing details. Methods to normalize the data for description of the cases and a system to describe different features unambiguously are needed. Keywords: refractory gold, host mineral, leaching, data analysis, case-based reasoning

Sep 1, 2012

By R. C. Miranda

This paper intends to demonstrate the applicability of tools for advanced process control and online particle size image analysis in crushing and autogenous grinding circuits. In a crushing plant, cameras are installed in the conveyor belts of the circuit products. The vision system continuously processes the acquired images and thus obtains the variation of the size distribution curve. From these measurements, the advanced control system can operate, for example, at the opening of the crusher, in order to keep the P80 in the desired range. In addition, through the power information and level of the crusher's chamber, it is possible to increase the capacity of the crushing circuit. If the crusher is not equipped with an automatic opening adjustment, a warning may be issued to the operator to provide this setting manually. In mineral processes that use autogenous and semi-autogenous grinding for fragmentation, obtaining online F80 through the vision system allows for manipulating the parameters of rotation speed and solids concentration, through which the amount of material at the critical particle size that is produced can be controlled. In addition, the noise produced in the mill can be measured and controlled. Thus, it is possible to prevent breaches and to optimise the mill capacity for grinding. Image analysis combined with an expert system that translates this information and acts to seek the most appropriate particle size distribution, brings greater stability to the process optimising the capacity of the equipment, which allows for significant gains in production.

Sep 1, 2012

By K. Gonçalves

One of Vale?s sponsored research project is aimed at the implementation of a practical scale-up procedure for flotation. In this context, detailed flotation kinetics characterization is of critical importance. This work presents the results of a campaign aimed at characterizing flotation kinetic parameters with respect to particle composition. MLA analysis was carried out for 40 narrow-sized iron ore particles with known flotation time from a controlled flotation kinetic test. The iron ore sample studied (59% hematite and 41% quartz) comes from a mine in the southeast of Brazil and the type of reagents applied are the same as used in the plant. For the reagent conditions tested, the overall rougher concentrate (sink) yielded 79.1%, pure quartz and hematite recoveries to the froth were 56.0% and 4.8%, respectively. The results from the kinetic tests show that the flotation rate of the particles doesn?t vary much (~0.03s-1) with composition and that the fraction of floatable particles in each grade controls the separation action. The results show that the rate of flotation is controlled by transport and that the selectivity is controlled by the fraction of floatable particle of each phase.

Sep 1, 2012

By P. K. N. Raghavan

Bauxite is the principal source for the production of aluminum metal which has gained tremendous importance over the years due to its versatility as a metal capable of substituting almost all of the non-ferrous metals, non metals like wood, plastics, fibre glass, etc. and even steel in many applications. 90% of the high purity alumina needed for the production of this wonder metal in the world comes from bauxite. Even though alternate methods have been developed to produce alumina from non bauxite sources, owing to the high capital and operating costs involved, Bayer process still retains the superiority among all the methods by virtue of its simplicity and favourable economics. Bauxite continues to be the perfect ore for alumina production and its remarkable utilization makes it the most important non-ferrous ore. Most of the Alumina Refineries in the world process different types of bauxite and that too from varied sources. The technology employed in the Alumina Refineries depends on the Bauxite processed, with an ultimate view to produce alumina of required quality in the most efficient manner. Bureau of Indian Standards (BIS) and Indian Bureau of Mines (IBM) had from time to time put forward bauxite specifications for metallurgical and other applications. However, these are found no fully based on alumina technology, present developments and availability of different types of bauxite in the country. The aim of this paper is to provide scheme of metallurgical grading of Indian Bauxite based on the background of alumina processing technologies and availability of various types of bauxite in the country. Efforts are made here to evaluate beneficiation techniques for central Indian Bauxite from the point of view of alumina production. Keywords: bauxite beneficiation, digestion, alumina, gibbsite, bohemite, diaspore

Sep 1, 2012

By A. Üçyildiz

Magnesium borates of varying compositions and properties are synthesized using different reagents and methods for the possible potential uses as termoluminescent material, anti-wear and anti-friction additive, fire retardant, catalyst for the conversion of hydrocarbons, whisker material and ferroelastic material. In the current work, the conditions for synthesizing MgB4O7 compound by high-temperature solid-state reactions were investigated using boric acid and magnesium oxide as the starting materials. The MgO:B2O3 mole ratios applied in the experiments were 1:1, 1:2, 1:3 and the thermal behaviours of each mixture were studied between 25~1200°C by TG/DTA analyses under static air atmosphere to find out the probable formation temperature of MgB4O7 phase. Considering TG/DTA results, freshly prepared boric acid and magnesium oxide solid mixtures were heated at predeter-mined temperatures and the phases were identified by XRD analyses. Accordingly, MgO:B2O3 mole ratio of 1:2, heating temperature of 950°C and a reaction time of 2 hours were selected as the optimum conditions for the formation of maximum amounts of MgB4O7. After obtaining solids prepared at the pre-determined optimum conditions, their chemical composition, IR spectrum, TG/DTA pattern, B.E.T. surface area value, particle size distribution and SEM images were deter-mined to point out the possible use areas. Experimental results showed that it was not possible to obtain pure product at the optimum conditions due to formation of minor amounts of t-Mg2B2O5 and the presence of some unreacted B2O3. The product synthesized has the potential for use as a corrosion inhibitor on some metal surfaces.

Jan 1, 2014

By S. Banisi, O. Farshid, M. R. Rozebehi, A. Bahar, A. Arghavani, M. Mahdavi

At the rougher flotation circuit of the Miduk copper concentration plant (Kerman, Iran) five column cells (CISA) with the diameter of 4m and height of 12m using static mixer type (MicrocelTM) spargers have been installed. Based on the initial design, columns should accept a feed rate of 625 t/h with 80% passing size of 90 µm and solids concentration of 28% and produce 88% of the plant concentrate (i.e., 22 t/h) containing 32% copper. Due to mechanical and processing problems this objective was never realized and theses columns were remained out of operation from the commissioning time (2005). A new attempt with the aim of returning these cells into operation started in 2013. The results of an extensive study indicated that spargers plugging due to the entrance of small amount (2 kg) of coarse particles (up to 2.5 cm) because of usual problems at the plant environment was the main reason of columns non functionality. With a change in the recycle pump inlet design to the column, which prevented the entrance of coarse particles to the spargers, the operation of the column significantly improved. It was found that in order to have a stable operation of the columns at the rougher stage the feed rate for each column should be reduced from 125 (design) to 70 t/h. The air superficial rate had to be also reduced from 1.9 (design) to 0.6 cm/s. A period of 10 days of continuous operation showed that the carrying capacity was 0.23 (g/min/cm2) which was significantly lower that of the design value (i.e., 0.58). The gas hold up was found to be lower than 10% beyond which columns started to move to the turbulent state indicated by "boiling" froth. The average life time of spargers was determined to be 20 days which considered to be very short. The average recovery and concentrate grade of these columns were found to be 68% and 32%, respectively. The high wear rates of spargers, unusually high level of maintenance and supervision needed and instability of the operation made the plant managers not to use column cells as the roughers.

Jan 1, 2014

By Anuttam Patra, Romain Bordes, Andreas Fredriksson, Tommy Karlkvist, Krister Holmberg, Kota Hanumantha Rao

The present investigation aims to develop and distinguish mineral specific reagents with two functional groups for use in flotation of calcium containing minerals. For this purpose, a series of dicarboxylate-based surfactants with varying length between the carboxylate groups (one, two or three methylene groups) were synthesized. As reference, a surfactant with the same alkyl chain length but with only one carboxylate group in the polar part was synthesized. The adsorption behavior of these new reagents on pure apatite and calcite mineral surfaces was studied using Hallimond tube flotation, FTIR and ? potential measurements. The relation between the adsorption behavior of a given surfactant on a specific mineral surface and its molecular structure over a range of concentration and pH values, as well as the region of maximum recovery were established. It was found that one of the reagents, with a specific distance between the carboxylate groups, was much more selective for a particular mineral surface than the other homologues synthesized. This selective adsorption of a given surfactant to a particular mineral surface relative to other mineral surfaces as evidenced in flotation studies is substantiated by ? potential and infra-red spectroscopy data.

Jan 1, 2014

By Paulo Sérgio de Oliveira, Joaquim D. Donda, Andreia C. Rosa

"The search for energy efficient technologies for comminution processes is constant in mineral processing studies, since those processes represent a major percentage of operational costs. In this context the use of stirred mills is increasing, especially for ultrafine grinding. Although many authors claim that these new equipment are more efficient than the conventional ball mills, there were very little chances to prove that in a practical way, since there are few industrial circuits where those technologies perform the same duty. Therefore, the regrinding circuit of Germano second concentrator offers an interesting opportunity: a vertical mill operating in parallel with two ball mills. During almost two years of operation, several sampling campaigns were conducted to evaluate the vertical mill performance and to compare the operational data of the three mills. The industrial data was also compared to jar mill tests results, which are monthly conducted in Samarco labs in order to predict the specific energy consumption required by the ore fed to these circuits. The vertical mill demonstrated the same ability to achieve the product specifications of the ball mills while proved to be able to reduce the medium specific energy consumption in about 40%."

Jan 1, 2014

By Slobodan B. Vujic

"Some twenty years ago, during construction of flotation in the “Veliki Krivelj” copper and non-metallic mine Bor, a computer supported system for remote controle of technological process was installed. Nowadays, the major part of equipment of this system is worn-out and technically old-fashioned. Having this in mind a decision was made to design a new computer supported information-management system for Flotation. The paper presents a concept and features of project solutions.For the requirements of remote monitoring and management of technological process in Flotation of “Veliki Krivelj”, Copper and non-metallic minerals mine in Bor, Yugoslavia (hereinafter: CNM Bor), a measuring-regulation equipment was implemented and a computer control system, adjusted for that time, built some twenty years ago. The major part of this equipment is today worn out and technically out of date.Having estimated that production and business activities could hardly be more efficient, operative and successful on one hand, and available mineral and other resources rationally exploited, the CNM Bor made a decision in 1999 to improve information-management function of Flotation. The idea was that the set task be realized through development and introduction into practice up-to-date integrated and computer-supported production-business information-management system. The first logic step in completion of this task refers to engineering-creative determination of information management system (hereinafter: IMS), namely to project elaboration.When considering the real system from technical, technological, organization, monitoring-management, logistic and business aspects, the Project on IMS of Flotation, should provide a rational, modern and, for the real system conditions, complete solution. The Project solutions should be based on the most recent knowledge from computer and measuring-regulation technics as well as from CIM concept (Computer Integrated Manufacturing)."

Jan 1, 2003

By Carin Laubscher, Francis W. Petersen, Jaap P. Smit

Waste streams, such as acid mine drainage, are often characterised by low pH values and high concentrations of heavy metals, dissolved solids, calcium and sulphates. Although lime remediation effectively removes most of the heavy metals as hydroxides, it is less effective at lowering levels of sulphates. Various methods of removing sulphates from effluents exist, such as precipitation with lime, precipitation with barium salts, co-precipitation with calcium carbonate, reverse osmosis, and ion exchange. Mintek developed a chemical precipitation (SAVMIN) process to treat acid mine drainage, which entails the addition of lime to precipitate the metal hydroxides, and the subsequent formation (precipitation) of calcium sulphoaluminate or ettringite. The key to the viability of the new technology lies in the correct use, regeneration and recycling of Al(OH)3 used to precipitate the ettringite. The water produced by this process is suitable for disposal to watercourses or for agricultural, domestic or industrial consumption. No brines are produced as the salts are converted to solid hydroxides, gypsum and calcium carbonate. The technology has been tested on several different waters in pilot plant campaigns. Results obtained indicate that potable water can be produced (containing less than 200 mg/L sulphate and no heavy metals) as long as the monavalent ions (Na+, Cl-, etc.) are within limits.

Jan 1, 2003

By Anatoly F. Usov, Vyacheslav A. Tsukerman

"The Russian scientists have developed a new energy saving method for an efficient destruction of the sturdy and hard materials (rocks, ores, frozen soils, concrete blocks ets.) - the Electric Pulse Discharge method of materials destruction (EPD). The detailed researches of a broad circle of problems connected to development EPD-disintegration of materials of a various nature and area of use are executed. The electrical and power characteristics of process, physical fundamentals of selectivity of a breakdown and destruction are investigated, the means of electric pulse splitting and refinements of materials are developed, the technological efficiency of disintegration of industrial minerals estimated.One of the most important characteristics of the EPD-disintegration of ores is the high selectivity of destruction, which provides a large ratio of useful minerals' grains opening, and at the same time, it destroy them less. This ensures in the subsequent stages of beneficiation of ores considerable increase of the extraction and improving the quality of concentrates.The technological tests of various industrial minerals have shown a possibility the EPD-disintegration, as a process that provides the best efficiency of disclosure of useful minerals in all types of ores. Technological and economic efficiency of the method of ore beneficiation is the highest for difficult beneficiated ores with rather low extraction by existing methods. The increase of extraction in this case can reach several percents. As a rule, at a EPD-disintegration the disclosure of mineral grains happens in earlier stages of material comminution than at a mechanical comminution, and with less damage of products. This promotes a simplifying the process of ore preparation and for reducing the power consumption."

Jan 1, 2003

By John Nell, Paul den Hoed

Carbochlorination tests were conducted with matched particle-size fractions of rutile, ilmenite and high-titania slag in a small bubbling fluidized-bed reactor. The effects of temperature, the type and proportion of solid reductant in the charge, and the fraction of Cl2 in the fluidizing gas were investigated. Tests confirm the need for solid carbon in the bed if chlorination is to run at high rates. With solid carbon in the bed, CO supplied with the fluidizing gas does not increase significantly the degree of chlorination after 75 minutes. Ilmenite is chlorinated more quickly than titania slag, which in turn is chlorinated more quickly than rutile. Rates of chlorination at 1100°C and 1000°C are much the same and significantly higher than at 900°C. Chlorination is associated with significant increases in particle porosity (even for rutile), which is brought about by the rapid initial chlorination of FeO and MnO (in ilmenite and slag) and (it is argued) by the chlorination of Ti2O3 which forms at high-energy surface sites. A reaction mechanism is presented; where possible, its validity is demonstrated by the support of empirical observations.

Jan 1, 2003

By T. B. M. Himawan

In this study, effect of thiosulphate and oxidation using oxygen were studied in arseno copper ore flotation. Single mineral study of chalcopyrite and tennantite in regard to the aforementioned techniques was also studied. Zeta potential, XPS, contact angle and floatability of single minerals were conducted for each treatment to understand the mechanism. It was revealed that the separation is best conducted in alkaline condition at where there will be interaction between thiosulphate and the mineral surface as well as the formation of hydroxide species in the oxidation using oxygen. From zeta potential of both thiosulphate and oxidation conditioning, it can be found that the reactivity of tennantite is much higher rather than chalcopyrite resulting higher rate of depression on both techniques as shown from contact angle and floatability of each mineral after treatment. XPS spectra confirmed qualitatively and quantitatively the existence of species responsible for the depression of each conditioning techniques. As for the copper ore flotation test, it is the oxidation using oxygen provides best performance after 60 minutes of oxidation. Keywords: tennantite, chalcopyrite, arseno copper ore A, thiosulphate, oxidation using oxygen

Sep 1, 2012

By Xin Tan, Changgen Li

"The floatabiliby of chelate CF-collector for zinc and lead oxide minerals was described. It found that CF-collector possesses a strong collection power for zinc and lead oxide minerals as well as excellent selectivity for the gangue minerals. A new technology of zinc and lead oxide flotation with CF reagent as a collector, lead nitrite as a activator and water glass as modifier was presented. The mechanism of interaction between reagents and minerals was discussed by means of adsorption, zeta potential, nephelometric titration, XPS and infrared spectra was investigated.CF-collector, newly developed by Beijing General Research Institute of Mining and Metallurgy (BGRIMM), is a kind of chelate collector for the flotation of oxide minerals. CF-collector mainly consists of N-nitroso-N-phenylhydroxylamine ammonium salt. The CF-collector was used for the selective flotation of scheelite in the Chinese plants.In this paper, the effects of the dosages of activator Pb(NO3)2 and depressants (sodium hexametaphosphate, polyphosphate, water glass and salified water glass) on the floatabilities of several minerals (cerussite, smithsonite, calcite, dolomite, limonite and quartz) as well as their mixtures were investigated in the presence of the CF-collector. The results show that the CF-collector is the excellent collector for selective flotation of cerussite and smithsonite. Pb(NO3)2 can selectively activate the oxides of lead and zinc resulting in a decrease of the CF-collector dosage. The sodium hexametaphosphate plus the salified water glass are the effective depressants for gangue minerals. Based on the above facts, the “CF process”, namely, used CF reagent as a collector, Pb (NO3) 2 as a activator, and sodium hexametaphosphate plus salified water glass as depressant, has been used for the flotation separation of the lead oxide mixtures or zinc oxide mixtures without disliking and heating. For the feed lead assaying 19.07%, the lead concentrate assaying 49.81% Pb at the recovery 80.69% was obtained after one step flotation. For the feed zinc assaying 12.85%, a zinc concentrate of assaying 29.56% Zn at recovery 83.87% was obtained."

Jan 1, 2003

By Leopoldo Gutierrez, Esau Arinaitwe, Marek Pawlik

"The effect of various polymers, including: anionic carboxymethyl cellulose (CMC), polystyrene sulfonate (PSS), humic acids (HA) and non-ionic hydroxypropyl cellulose, on the wettability of Athabasca bitumen was evaluated through dynamic contact angle measurements using the captive bubble technique. The tests were carried out as a function of pH at a constant ionic strength (0.01 mol/L sodium chloride). The evolution of the three-phase contact angle between the solution, bitumen and an air bubble was followed as a function of time over a period of ~6 minutes. The contact angle data were modelled using a first-order kinetic equation. The results were analyzed in terms of the initial contact angle, the evolution rate constant, and the steady-state contact angle value. In the case of anionic polymers, a pronounced decrease in the initial contact angle value was observed at pH 3. Under acidic conditions, there was no significant effect of CMC observed on the steady-state contact angle value but PSS and HA significantly decreased the steady-state contact angle value. At pH 8.5. the anionic polymers did not affect the wettability of the bitumen surface but they significantly decreased the contact angle evolution rate. These results suggested that CMC is not capable of permanently lowering the hydrophobicity of bitumen, and the polymer only slowed down the evolution of the contact angle to the steady-state value. The results also showed that polystyrene sulfonate and humic acids were capable of making bitumen hydrophilic but only under acidic conditions. Only hydroxypropyl cellulose (HPC) produced a large decrease in the steady-state contact angle under alkaline conditions (pH 8.5). The kinetics of contact angle evolution in the presence of HPC was also drastically lowered. The results were discussed in terms of the chemical composition of the polymers and their different affinities towards the bitumen surface."

Jan 1, 2014

By B. Z. Wu

The ore dressing of tin-polymetallic lean ores is a difficult problem and the research emphasis in domestic nonferrous metals mining field. Through research and tackle key problem,and in order to supply reference in dealing with the same types ores, this paper expatiates the exploiture and appli-cation of six item new technology and technics in ore dressing of tin-polymetallic lean ores. It include the technics of multi-step compounding disposing tailings, grinding step by step, grinding and processing circularly technology, high thickness without circle flotation technology, dispersedly flotation tin step by step technology, exceed fine lean plumbum stibium zinc flocculation flotation technology, the synthetically recovery of waste water after ore dressing technology.

Jan 1, 2014

By Khoi Nguyen, Keeney. Luke

An outcome of geometallurgical mapping and modeling is the generation of continuous down hole profiles of quantitative geometallurgical attributes at assay scale. These attributes vary from traditional routine data collection methods such as assays and geotechnical logging (e.g. RQD, Fracture Frequency), to new measurements including petrophysical attributes, EQUOtip hardness data and modelled estimates of metallurgical performance indices (e.g. A*b, BMWi). Highly variable continuous geometallurgical data with high spatial resolution can make it difficult to identify spatially continuous domains. An automated method based on the well known time series analysis technique of cumulative summation (CuSum) has been developed which uses statistical analysis to identify domain boundaries in down hole profiles. A bootstrap analysis automatically identifies potential domain boundary locations with associated confidence levels and a series of t-tests determine the significance of defined populations. A hierarchical clustering algorithm is applied to results to enable data sensitivity to be taken into account. The method produces statistically significant populations and is suitable for application on either single or multiple drill hole datasets. Domains defined preserve the inherent variability of the continuous down hole data and provide a method for scaling up variability data (i.e. assay interval scale) to mine scale (i.e. bench scale, block model). A major advantage of the method is its ability to provide suitable input parameters for use in spatial modeling of non-additive and non-linear geometallurgical attributes through conditional simulation techniques.

Jan 1, 2014

By Shankar Narasimhan

Data Reconciliation is a technique that has been developed more than fifty years ago and has been refined over the past few decades and is now being deployed routinely in several process industries such as refining, petrochemicals, mineral processing and hydro-metallurgy. The main aim of data reconciliation is to obtain accurate estimates of all process variables and parameters using plant measurements that are invariably corrupted by random errors and may also contain biases and other gross errors. These reconciled estimates are subsequently used either in offline exercises such as simulation, retrofitting, and de-bottlenecking or in online optimization and control applications. In this presentation, a brief history of data reconciliation, its assumptions, and uses are reviewed. New developments in this area are highlighted such as robust data reconciliation to handle model uncertainties, and reconciliation using identified models derived purely from operating data. Several case studies in the mineral processing industries reported in the literature are also highlighted to indicate the potential benefits of this technique.

Sep 1, 2012

By Y. G. Zhu, G. B. Zheng, Z. B. Qian, X. R. Zhang, A. J. Ren

"Based on PMA polymer, two kinds of novel macromolecular depressants, PMTA and PMA-PDTC, were designed and synthesized. PMTA was used for desilication in hematite reverse flotation. PMA-PDTC was used in the separation of Cu-Pb concentrate as galena depressant. The micro-flotation results showed that PMTA exhibited a good depression performance compared to starch. We found that 98.29% of hematite was depressed with a grade of 65.24% at pH 11 with 12 mg/L dosage. The flotation separation results of Cu-Pb concentrate demonstrated that PMA-PDTC was an effective depressant for galena in separating galena from chalcopyrite. When IPETC was used as collector, at pH 8.5, the flotation separation tests demonstrated that Cu concentrate was obtained with a grade of 28.89% containing 12.12% Pb.INTRODUCTIONThe role of depressants is crucial in the separation of oxide or sulfide minerals, for example, the desilication in hematite concentrate and the separation of Cu-Pb concentrate.It is well known that, in current reverse flotation processing of hematite, starch is a traditional depressant for hematite. Most research focus on the modification of starch [1-3]. Although its depressing ability is enhanced in some extent, its own shortcomings is still existed. So, it is important to develop a new hematite depressant instead of starch.In the separation of chalcopyrite and galena, because of their extremely similar floatability, it is difficult to realize the separation of these two minerals. Traditionally, there are two methods widely used in the separation of Cu-Pb concentrate by depressing chalcopyrite with cyanide [4] or depressing galena with dichromate [5] in most cases. However, these two inorganic depressants are toxic and hazardous. Their use could cause heavy pollution problems and a large loss of precious metals. In order to adapt to the requirements of sustainable economic development and environmental protection, the research and development of green and environmental depressant has gained more and more significance."

Jan 1, 2018