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By Mike Dry

Conventionally, lithium-bearing brines are processed via solar evaporation, chemical purification, and either electrolysis to lithium hydroxide or precipitation of lithium carbonate. Lithium-ion battery technology and electric vehicles are forecast to greatly increase the demand for lithium, but not all lithium-bearing brines are amenable to the conventional extraction process and new approaches are being developed. The chemistry associated with conventional lithium extraction is outlined and two new approaches are discussed.

By I. D. Reznik

The flowsheets of converter matte production from sulphide copper - nickel and oxide nickel ores on Severonickel and Yuzhuralnickel integrated ,;corks are given. The cobalt behaviour in electrosmelting and autogenous ore smelting, converting and converter slag cleaning is observed. A list of acticles published in the 80 th is given.

Jan 1, 1993

By S. A. Shuey

The present industrial practice used to separate aqueous cobalt from nickel is multistage solvent extraction processing. This paper describes a different but simpler treatment technology. The proposed technology has been applied to cobalt/nickel hydroxide intermediate solids produced from the treatment of Electrochemical Machining (ECM) waste sludge, The process consists of dissolving the cobalt/nickel hydroxides in basic cyanide solutions. Cobalt and nickel form aqueous .solution metal cyanide complexes. Nickel can be selectively precipitated from the solution as a nickellic hydroxide solid. Cobalt can be recovered from the leach solution by precipitation of a cobaltous/cobaltic cyanide double salt. The double salt product can then be subsequently treated to produce an appropriate cobalt product. The process chemistry, proposed fiowsheet and preliminary reagent costs are presented and discussed.

Jan 1, 1998

By Meifeng Zhi

Separation of uranium and molybdenum in the alkaline leach solution of a U–Mo ore was studied. A process of acidification-solvent extraction-precipitation uranium and molybdenum was determined. The influences of solution acidity and phase ratio of acidic scrubbing on separation of uranium and molybdenum were examined. The molybdenum extraction equilibrium isotherm was drawn. The results show that the separation of molybdenum and uranium can be achieved by acidifying the alkaline leach solution, solvent extracting molybdenum using trialkylamine at equilibrium pH 2.5, and scrubbing the loaded organic phase using sulfuric acid solution. The strip solution can directly precipitate ammonium molybdate. Uranium can be directly precipitated from the raffinat

By Tina Maniatis

Applied Biosciences has developed a biological technology for removal of arsenic, nitrate, selenium, and other metals from mining and industrial waste waters.The ABMet® technology was implemented at a closed gold mine site in Canada for removing arsenic from tailings pond water. The system included six bioreactors that began treating water in the spring of 2004. Design criteria incorporated a maximum flow of 567 L/min (150 gallons per minute) and water temperatures ranging from 10°C to 15°C. Influent arsenic concentrations range from 0.5 mg/L to 1.5 mg/L. The ABMet® technology consistently removes arsenic to below detection limits (0.02 mg/L). Data from the full scale system will be presented, as well as regulatory requirements and site specific challenges. Keywords: Arsenic, Sulfate Reduction, Metal Sulfide Precipitate, Biological Water Treatment

Jan 1, 2005

By Travis Knight

Mixed uranium and refractory metal carbide systems have been proposed for space nuclear power and propulsion applications. Solid-core space nuclear reactors could be utilized for low- earth-orbit (LEO) to geosynchronous-earth-orbit (GEO) transfers, manned missions to the moon or mars, and orbiter missions to the outer planets. However, these high performance space nuclear reactors present some challenging materials engineering requirements for operating in a high temperature, high radiation, and hot hydrogen environment. Since the RoverNERVA programs were concluded in 1973, significant advances in ultrahigh temperature materials technology have been made which can be applied to the development of an advanced solid-core nuclear fuel. Nuclear thermal propulsion (NTP) was first studied in the U.S. beginning in the mid-1950's during the RoverNERVA programs. During that time, about 20 rocket reactors were built and tested. More recently, Russian nuclear rocket reactor tests with pseudo-ternary carbide nuclear fuels (U, Zr, Nb)C and (U, Zr, Ta)C have been operated at temperatures as high as 3300 K for one hour. This study examined the processing parameters for fabricating the pseudo-ternary carbide, (U, Zr, Nb)C.

Jan 1, 1999

By Guan-Yong SHI, Cong Wang, Zhi-he DOU, Ting-an ZHANG, Shi-gang FAN

Based on the pre-works, this paper proposed a new short stage process of the intensify aluminothermy reduction by the stage to prepare high titanium ferroalloy with low O and Al contents. We investigated the effects of Al and Ca and Si combination reduction agent, slag type and step-up reduction conditions on the Al content and distribution in the alloy. The results show that the step-up reduction can not only reduce effectively the oxygen content in the alloy, but also reduce effectively Al content. For instance, the oxygen content in high titanium ferroalloy is within 1%~4%, and the Al content is within 1%~5%. Its quality reaches the requirement of high titanium ferroalloy prepared by remelting process.

Jan 1, 2015

By David Melgaard

A significant emerging recycling, waste minimization problem stems from legacy waste from the nuclear weapons program and from production of power using nuclear fuel. Premium quality metals used in nuclear plants become contaminated, making them unsuitable for reuse. Consequently, decontamination studies were conducted to evaluate the decontamination capacity and partitioning effeetiveness of Electroslag Remelting (ESR). Eight laboratory melts were conducted to evaluate the efficacy of using ESR to transport radionuclides from the liquid metal phase to the liquid flux or slag phase. To determine the decontamination effectiveness, several surrogate compounds for uranium, plutonium and other fission products were added to the melts. During the melts, the melting rate was varied, typical slag additives were used, and two different slag compositions were evaluated. The resultant post-test ingots and slag were then analyzed to determine the partitioning of the surrogates. ESR generally proved very effective in removing contaminates from the metal with a few noted exceptions. -

Jan 1, 2003

By R. Shimpo

Equilibrium calculations by a computer may sometimes fail in giving solutions when the system includes a large number of components and more than three phases, and especially when no definite information about stable phases is given. An improved method of calculation is presented in which the number of phases need not to be initially fixed, phases can appear or disappear in the course of' calculation and a new method is combined with the Newton-Raphson method to obtain solutions easily. The improved method is applied to the copper smelting operation and all the successive stages of the operation are successfully simulated.

Jan 1, 1983

By Qingyu Deng, Shiwei Ma, Wang Hua, Guibao Qiu

"The flow properties of the blast furnace slag bearing high TiO2 at high temperature like the viscocity may change a lot due to the formation of the carbonitride inside, causing serious problems on the separation between the metal and the slag. Therefore, the critical condition of the formation of Ti(C,N) in blast furnace is vital importance for the ironmaking process with iron ore bearing titania. In this study, the formation of Ti(C,N) in blast furnace and the influences of various factors on the Ti(C,N) formation are investigated by FactSage. It is found that the mass of Ti(C,N) would reach the maximum at 1480 oC, and the product is mainly TiN below 1620 oC, while it is mainly TiC above 1620oC. The order of the factors by the importance from strong to weak was: temperature, the content of TiO2 in slag, basicity of slag, the content of MgO and Al2O3.IntroductionThe titanium dioxide (TiO2) in iron ore bearing titania will be partly reduced by carbon to titanium carbonitride (Ti(C,N)) in blast furnace, causing serious problems on the separation between the metal and the slag because of the change of flow property. Therefore, the critical condition of the formation of Ti(C,N) in blast furnace is vital importance for the ironmaking process, especially for the smelting of iron ore bearing titania. Extensive experimental data in regard to the formation of Ti(C,N) has been reported in numerous papers[1-6]. However, only some discrete data can be obtained by experiment, and it is difficult to detect the mass of Ti(C,N) in slag. In addition, the experiment is difficult to be proceeded when the temperature is above 1600oC. Therefore, it is very difficult to make clear the critical condition of the formation of Ti(C,N) by experiment."

Jan 1, 2012

By Dong Hoon Han

The sulfation rates of magnesium oxide and calcium oxide (molar ratio 7:3) contained in calcined CMA ( calcium magnesium acetate) by SO2 were measured. The experiments were carried out in the temperature range 700 to 1100 °C and under the SO2 concentrations of 0.3 to I mol % (5 % 02). In the low-temperature range below 830 °C the reaction produced CaSO4.3MgSO4 and unreacted MgO, but no MgSO4 phase. The formation of CaSO4.3MgSO4 phase has a significant implication in that it allows the utilization of MgO for SO2 removal whereas the sulfation of MgO from conventional sources is so slow that it is of no practical interest. Thus, the calcined CMA can remove SO2 at lower temperatures than conventional SO2 absorbents and at a greater capacity. Above 950 °C only CaO reacts with SO2, but at a much greater rate than the calcined Ca(OH)2, which is one of the most reactive SO2 absorbents.

Jan 1, 1998

By Omid Marzoughi

Chromium has a wide range of applications, including as an alloy addition in various steels and also as a corrosion resistance coating. Carbothermal reduction of chromite ore (FeCr2O4) in a submerged arc furnace is an important industrial process for extracting chromium, but the energy consumption is excessive. It is suggested that one area for future research is the low temperature carbothermic solid state reduction of chromite to produce an intermediate product, which can subsequently be upgraded to ferrochromium. In this regard, a thermodynamic model has been developed to investigate this process and the effects of temperature, carbon additions and ore composition on the recovery of chromium and the grade of the ferrochromium, have been studied. Further development of the model may allow it to be applied to the simulation of other processes for the recovery of chromium from chromite ores.

By Ma Shao Xian, Li Dong, Li Zhen Guo

"The new type shaft calciner ( SK-10 Serials) is developed and designed by CADRE itself on the basis of the conventional shaft calciner. The actual application in a number of calcinations plants have proven that they are of very good effect. Calcined coke calcining heated by the shaft calciner has a high quality, lower lost by fire. The shaft calciner needs no additional fuel when it is working. Anode Carbon Plant and calcined coke Plant commonly used the shaft calciner in domestic. The waste heat from the shaft calciner can be recuperated to generate electricity and to make the steam for produce. Exhaust waste heat is recovered by 90% or more. The new type shaft calciner's structure is optimized by computer simulation for fire-wall structure, combustion air to fuel ratio, volatile combustion is fully in use, furnace cooling zone structure, the exhaust smoking structure and calciner heat balance. Furnace structure and production operating parameters has been got the best optimized results. This paper introduces the working principle and characteristics of the shaft calciner - the equipment for calcining of the petroleum coke. It also demonstrates measured process parameters of the new type shaft calciner. Through comparison with the rotary kiln and conventional shaft calciner, it proves its own technical characteristics and advantages: higher capacity, high quality products, provides more energy for power generation, equipment operation and maintenance costs lower.IntroductionChina's petroleum coke market is mainly dominated by the delay raw petroleum coke. Rotary kiln and shaft calciner are the main process equipment for calcined petroleum coke. As the shaft calciner burning less, no external fuel, waste heat utilization is high, long service life, the utilization rate in China is more extensive than the rotary kiln."

Jan 1, 2012

By J. Rastas

The recovery of lead, silver and gold from existing and potential zinc process residues using a sulfidization-flotation method was investigated on a laboratory scale. The following residues were tested: neutral leach residue, high acid leach residue, and hematite residues. The sulfidization of lead and silver is carried out at low pH by the addition of a stoichiometric amount of sulfide at a controlled rate. To increase the particle size of the sulfides, seeding with synthetic lead and silver sulfides -is employed. The flotation is carried out at pH 2-4 using low pH-collectors such as dithiophosphates and dithiophosphinates. Special attention must be paid to the role of oxygen in the conditioning stage. The effect of different parameters on both the sulfidization and the flotation has been evaluated. Recoveries of 85-90, 90-95 and about 80 % were obtained for lead, silver and gold, respectively. Typically, concentrates containing 50-60 % lead, 3-5 kg/t silver and 10-15 git gold were produced.

Jan 1, 1990

By H. Virtanen

Outokumpu copper refining operations have a long history of expansions and application of new technologies. Outokumpu is a name known around the world for technological excellence in the field of base metals, and part of the policy of operations is continuous investment and investigation in new technologies. The results of this hard work sometimes are immediate and sometimes take years. The work done during the last years at the Outokumpu Harjavalta Metals copper refinery, together with a sister technology group Outokumpu Wenmec, has started to bear fruit in terms of the following radical developments and advances that are and will be applied to assure Outokumpu's position as the technology leader and a low cost and safe producer. Some of the developments discussed include the new anode and cathode design, mechanised electrode handling, cell design incorporating features facilitating full automation, automated short circuit detection and removal, automated on line anode slime removal, and high efficiency and intensity refining.

Jan 1, 1999

By Jussi Vaamol

A commercial CFD-code was used to solve isothermal flow fields of gas and liquid in a Peirce-Smith converter. The model was validated with a 1/4 scale water model, and parametric study. Limits of the modeling technique used were recognized, but calculated results indicate that the present model predicts the general flow field with reasonable accuracy. The model was used to examine general flow conditions in an industrial scale PS-converter. Typical scaling factors of physical models were also evaluated with the aid of predicted bubble distribution, patterns of the flow fields and magnitude of flow velocities. The numerical simulations were found to open new viewpoints to the fluid dynamic related phenomena in the PS-process.

Jan 1, 1998

By Michal Rzyman, Nakamura Takashi, Shibata Etsuro, Grabda Mariusz, Oleszek-Kudlak Sylwia

"Thermodynamic considerations indicate that heavy metal oxides should easily react with HBr, the main gaseous product from the thermal decomposition of tetrabromobisphenol A (TBBPA), forming low boiling point metallic bromides suitable for volatile separation. Mechanisms and kinetics of the bromination reactions must be well recognized prior to developing of a new treatment for the simultaneous recycling of plastic waste containing brominated flame retardants (BFRs) and metal oxides (printed circuit boards, automotive shredder residue, plating sludge, metallurgical dusts). In this work, a differential scanning calorimeter and laboratory-scale furnace were used to investigate the possibility and conditions of the bromination of ZnO by product of thermal decomposition of TBBPA. The formed solid, condensed and gaseous products were analyzed by X-ray diffraction analysis, electron probe microanalysis, inductively coupled plasma analysis, ion chromatography and gas chromatography coupled with mass spectrometry. Introduction Tetrabromobisphenol A (TBBPA) is the largest volume brominated flame retardant (BFR) in production today and is used in more than 70% of the world’s electronic and electric (E&E) appliances [1]. The growth in the production of E&E products and the fact they become obsolete so quickly cause significant problems in the safe disposal and recycling of the electrical and electric waste (E-waste) and other BFR-containing waste [2]. Among various treatment processes, thermal methods are most useful since they allow the recycling and recovery of both the organic and inorganic fractions of the waste. However, incineration of the BFR-containing wastes results in the emission of hazardous organobromine compounds, while the main portion of bromine released from decomposed BFRs is present in flue gas as hydrogen bromide (HBr) [3]. HBr, which is known to damage incineration systems, seems to be a very effective bromination agent for many metallic oxides present in waste. The concept of this study is to take advantage this of its property."

Jan 1, 2008

By Huimin Lu, Min Li, Jinghua Zou

"Zeolitic imidazolate frameworks (ZIFs) are new type of porous materials, form inerratic polyhedral in three-dimensional with large cages and small apertures, and appear structural diversity. Their hole size can be adjusted. These materials have high selective adsorption capacity to carbon dioxide. In this paper, zeolitic imidazolate frameworks were synthesized by solvothermal synthesis method with dimethylformamide (DMF) as solvent and structuredirecting agent, divalent metallic ions as cation, and imidazole as ligand. The crystals were characterized with XRD, SEM for their crystal structures and physical properties, the adsorption of the crystals for carbon dioxide was also tested, and the result suggests that these porous materials have a capacity of 1.35ml/g for storing carbon dioxide at 273 Kelvin under ambient pressure.IntroductionGlobal warming caused by the increase of carbon dioxide in the atmosphere has become one of the main environment problems, contemporary research has focused on ways to slow or stop this trend. CO2 capture has attracted attention due to the potential to trap and sequester large amounts of CO2 from concentrated sources such as power plants [1]. Traditional technologies in capturing CO2 include absorption by aqueous amines [2]. However, utilization of this process is energy intensive and expensive. Carbon dioxide storage materials investigated so far can be divided into two categories: chemical storage adsorbents and physical storage media [3]. The first kind of materials can chemically adsorb carbon dioxide within their structures and need thermal energy to release the adsorbed carbon dioxide. The examples of the chemical adsorbents include aqueous amines, gas-hyperbranched aminosilicas [4]. The physical adsorbents store carbon dioxide by physical adsorption of carbon dioxide at elevated pressure and release the adsorbed carbon dioxide at low pressure. The physical adsorbents that have been investigated for carbon dioxide storage include zeolites, carbonaceous materials and other porous materials. Until recently, a new type of microporous material, known as zeolitic imidazolate frameworks (ZIFs), has been reported as promising adsorbents for carbon dioxide storage [5 ~ 10]."

Jan 1, 2010

By Liyuan Chai, Bing Peng, Ji Peng, Di Yu

"Electric arc furnace (EAF) stainless steel dust has been classified as a hazardous waste by various government regulatory agencies as it releases heavy metals to environment. The solidification of EAF dust is to stabilize the hazardous components to the amorphous silica-alumina-based clays. The process of solidification is investigated and the softening temperatures of dust and additive clay mixtures are measured for economical thermal treatment. The results indicate that the mixture of dust and local clay with the ratio of 1:1 has the lowest softening temperature 1100 °C and it could pass the toxicity characteristics leaching procedure (TCLP) test for the environmental regulatory limits after thermally treated at softening temperature for 15 min. Major phases of thermal solidification product clinker are CaAl2Si2O8, (Fe, Cr)2O3, (Fe, Mg)(Cr, Al)2O4 and Al6Si2O13.IntroductionThe yield of stainless steels in China arrived to 10 million tons in 2006 and more than 0.2 million tons of stainless steel dust are produced annually. Approximately 1-2 wt.% of scrap charged to an electric arc furnace (EAF) enters the off-gases and then is converted into the dust and reported to the bag-house. The disposal or landfill of the dust becomes a serious environmental problem in China due to the increased production of stainless steels in recent years. The dust contains elements such as chromium (Cr), nickel (Ni), lead (Pb), zinc (Zn), cadmium (Cd) and their solubility in leaching media exceeds the environmental regulatory limits [1]. Even though easily feasible for low-grade MgO, it is not appropriate to stabilize the heavy metals from the heavily contaminated soils after the dust landfill [2]. Several dust treatment technologies have been developed and they can be divided into two types. One is to recover the metals from the dust [3, 4] and another is to stabilize hazardous components present in the dust [5, 6]. Recycling of the dust generated in EAF is a remediation option for cleaner production. Direct recycling of EAF stainless steel dust was developed to recover the metal value from the dust and protect the environment [7], but it was only suitable for the dust with high contents of Ni, Cr and Fe. As for the dust with low valuable metal content, thermal solidification is an appropriate choice for the dust treatment."

Jan 1, 2012

By A. J. Schindler, F-P Sawyer, T. Logan, M. L. Shutey-McCann, R. M. Perry

"Test work on biooxidation pretreatment of low-grade refractory gold ores has been ongoing at Newmont Gold Company since 1988, including laboratory testing and pilot biooxidation heaps (360 to 23,000 tonne). Metallurgical results of the biooxidation process utilizing Thiobacillus ferrooxidans (T. ferrooxiddans) have culminated in the design, construction, and operation of a biooxidation demonstration facility. The facility has processed 708,000 tonnes of refractory ore, using a batched process with separate pads for biooxidation and ammonium thiosulfate gold extraction. Siliceous sulfidic refractory (SSR) and carbonaceous sulfidic refractory (CSR) ores are treated separately during biooxidation pretreatment unit operation. Following biooxidation, the ores are neutralization with lime and placed on oxide leach pads or stacked on the ammonium thiosulfate leach pad. Gold is leached with either cyanide for SSR ores or ammonium thiosulfate for preg-robbing CSR ores.This paper will only address the biooxidation pretreatment process of the SSR and CSR ores.AcknowledgmentsThe authors appreciate the cooperation and approval of Newmont Gold Company Carlin Operations management for its support and permission to publish this paper. The paper draws on efforts and assistance of the following people and several others which are to many to list who participated over the past five years in bringing this project to its fruition: Dr. James A. Brierley, Chief Microbiologist, Newmont Metallurgical Services; Dr. Rong-Yu Wan, Metallurgical Manager, Newmont Metallurgical Services."

Jan 1, 1997