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By M. D. Stephens

A new, one-step process for extracting titanium from titaniferrous materials has been demonstrated. In the process, depleted uranium tetrafluoride (DUF 4), a solid, is mixed with ilmenite (FeTi03) and heated to 900°C. Titanium is extracted in the vapor phase as titanium tetrafluoride (TiF4) and the DUF4 is converted to uranium-iron oxide. The process has been found to selectively fluorinate the titanium in ilmenite and is capable of producing high purity TiF 4 with very low iron content. TiF 4 can be collected by condensation or through reaction with a fluoride salt such as NH4F, KF, or NaF. The TiF4 produced from the process can be used to make titanium metal, titanium oxide, or fluorotitanate compounds. Since the fluorination process is highly selective for titanium, it avoids many of the separations and waste issues common to other titanium extraction processes.

Jan 1, 2001

By Ramana G. Reddy, Yuxiang Peng

The long-term corrosion behavior of Haynes 230 (H230) alloy in MgCl2–KCl eutectic salt was evaluated at 1273 K for 500 h in Ni crucible in argon gas. The results showed H230 alloy has good corrosion resistance. In addition, corrosion was noted to occur by depletion of Cr, which was deposited on the Ni crucible. Based on the calculation of Gibbs energy of Ni-Cr alloy and exchange current density of Cr in MgCl2–KCl, the Tafel model was constructed to investigate the corrosion potential and rate. The galvanic corrosion can be explained as the predicted results were in agreement with the experimental data.

Mar 1, 2017

A study was undertaken to remove the Se from waste solutions using a raw form of the biomass called Iota Chips derived from the seaweed, Eucheuma spinosum. Removal of Se from solutions was investigated as a function of time, pH, conc. of Se in solution (0.1 to 100 ppm) and lota Chips to liquid ratios of 10-2 to 10-5. For solutions containing initial conc. of 0.1 ppm Se, with the addition of Iota Chips at a solid to liquid ratio of 10-3, the Se conc. decreased to 0.03 ppm in about 3 hours. Iota Chips absorption capacity to the Se and its application to the treatment of the metallurgical processing effluents are discussed.

Jan 1, 1992

By Kiyoshi Shibata

A new assessment model has been proposed for metal production and its recycling system. The model consists of three processes, smelting of ore, cascading and upgrading of metal scrap. The present approach is to assess the total energy consumption of the system, by introducing two equations for describing the relationships between critical impurity content and the mass of production or scrap recycling. The total energy consumption in the system can be described as a function of recycling rate and performance of the upgrading process. The present model suggests that the impurity removal efficiency and yield in the upgrading process are essential to reduce the energy consumption in the systems. Especially, such points should be explicitly controlled in recycling of aluminum. The potential capability of this model was also discussed by obtaining several quantitative information required for the process design and the operational control of beneficial recycling of metals.

Jan 1, 1998

By Marco Olper

After two years of extensive research a new and innovative modification to the CX-EW process has been exploited. This process, called CX-EWS, avoids completely all the critical aspects of the previous process which affected the cost of the energy, of the chemicals and of The maintenance of the insoluble anodes. All these benefits reflect a saving of about 30% of The operating costs compared to the present traditional production and allow for a total operating costs of less than 6.5 cts/lb. lead (net of raw material cost). With this new technology it is allowed for the first time the treatment in the same plant facilities of both primary lead sulphide concentrate and spent batteries. The paper describes the technical and economical aspect of the new process with a feasibility study for 150,000 t/y spent battery facility throughput.

Jan 1, 1995

By Sepp Härkki

The energy crisis in Finland after World War I1 together with a sharp rise in the price of energy caused Outokumpu Oy to consider replacing the electric furnace smelting of copper concentrates by some other method. The flash smelting method developed under these circumstances offered a considerable saving of fuel through the utilization of the reaction heat of sulphides and yielded a high recovery of sulphur in the form of acid. The pilot plant testing of the new process was carried out in the years 1947 - 1948. The process was adopted for the smelting of copper concentrates (1) (2) (3) on a commercial scale in 1949 and applied successfullv to the smelting of -nickel concentrates' at the Harjavalta Works in 1959 (4) (5) (6). In 1962 Outokumpu adopted another type of flash smelting where elemental sulphur is recovered from the gases after the thermal decomposition of pyrite in the flash smelting furnace (7) (8): In recent years, the copper-nickel flash smelter and pyrite process have been combined to produce elemental sulphur instead of SO2 from the smelter gases (9) (10). The basic idea of the Outokumpu flash smelting process for sulphidic ores is that the conventional methods with separate roasting and smelting operations are replaced by a combined roasting, smelting and part-converting process carried out in one unit. The heat generated from the exothermic reactions can thus be used for smelting the ore so that only a small amount of additional fuel is needed. The characteristic of the method is also that the dried, fine-grained concentrate is smelted in suspension, which offers the best conditions for rapid reactions. The recovery of waste heat from the furnace off-gases had been considered already in the original flash smelting system. A

Jan 1, 1976

By C. A. Morais

The present work describes the development of an efficient and relatively simple process to obtain high grade CeO2 from a mixed rare earth chloride solution. The process involves cerium oxidation and precipitation by addition of a KMnO4-NaCO3 solution. The experiments were carried out at room temperature (25 1° C). The results indicated that the major parameters affecting cerium recovery are the molar ratio of KMnO4/Ce, the initial acidity of the chloride feed solution and final pH of Ce(OH)4 precipitation. In strong acid solutions (pH < 1), the oxidation of Cl to Clo took place in addition to the oxidation of Ce(III) to Ce(IV), so increasing the permanganate consumption. Conversely, low acidity (pH >3) led to coprecipitation of the other rare earth elements. Under the selected conditions, cerium was selectively precipitated as ceric hydroxide, together with some manganese dioxide. Further purification was carried out by the dissolution of Ce(OH)4 in HCl, followed by precipitation as cerium carbonate. The filtrate was neutralised with a Na2CO3 solution in order to recover the associated rare earth elements for further separation. The final product, assaying 99.7 % CeO2, was obtained with a recovery of nearly 100%.

Jan 1, 2003

By Baozhong Ma, Qian Li, Yonggang Wei, Shiwei Zhou, Bo Li, Chengyan Wang, Hua Wang

The magnesium-rich nickel oxide ore (w (Ni) =1.09 %, w (MgO)=29.08 %) mixed with 6 % and 8 % anthracite were roasted at different temperatures. XRD and SEM/EDS techniques were utilized to characterize the phase and microstructure transformation of the ores. The results show that lizardite and chrysotile of raw ore were converted into forsterite and enstatite during reduction roasting process. Simultaneously, iron and nickel oxide were reduced and migrated from the initial magnesium silicate. Fe3Si were formed when the roasting temperature went up to 1300 ℃ and 1350 ℃, and a small amount of Ni was observed in it. Temperatures got too high were not benefit to the polymerization of ferronickel.

Jan 1, 2015

By Eric J. Beckman

Recovery of metals from dilute solution, whether the matrix is solid, or liquid, remains a considerable technical and financial challenge. Methods currently exist whereby metals can be extracted from either type of matrix, yet these methods consume significant quantities of reagents and can also generate multiple waste ,streams in the process. Technology developed in our lab allows efficient application of environmentally-benign CO2 to a number of separation problems involving metals. For example, we have employed biphasic mixtures of C02 and water as a green acid leach medium. Metals have been extracted from a steelmaking process residue and then recovered as metal carbonates through depressurization. In this process, metals are extracted and recovered without the use of reagents other than CO2 and water, and CO2 is sequestered as a solid. In addition, through synthesis of Cal-miscible phase transfer agents, we have shown that CO2 can replace the organic solvent currently used in refining of precious metals, The sensitivity to pressure of phase behavior in a CO2-mixture may allow significant streamlining of the process as well. Finally, CO2 soluble chelating agents have been used to extract toxic metals from acidic effluent such as that found in plating facilities.

Jan 1, 1999

By Jun Li, Lingling Zhang, Daqiang Cang, Guizhou Zhao

Pilot trial of direct modification of molten blast furnace slag and production of high acidity coefficient slag wool fibers were investigated nearby a blast furnace. Molten blast furnace slag discharged from blast furnace and then directly flow into specialized modification furnace and quartz was simultaneously added into the molten slag as modification agent. The modified molten slag was electric heated to 1500–1550 °C and then the melt was produced into slag wool fibers through high-speed centrifugation method. Melt with acidity coefficient of 1.2, 1.4, 1.6 and 1.8 were investigated and fibers with corresponding acidity coefficient were produced. Slag wool fibers with shot content of 5.5, 5.8, 6.2, 6.8% and average diameter of 4.5, 4.9, 5.6, 6.4 lm for four samples were successfully produced, respectively. Total energy consumption and production costs decreased by 50–70% compared to traditional cupola furnace method. This method provides an energy-saving and emission-reduction technology for the direct utilization of molten blast furnace slag.

Mar 1, 2018

By Ze-Qiang Xie, Bai-hui Wang, Feng Chen, Ling-zhi Yang, Yu-feng Guo

In this paper, based on the big data in steelmaking process, equation about the relationship between steel composition (especially the oxygen content) and the element yield is established by using mathematical analysis method to analyze the factors influencing yield. Meanwhile, combining the alloy yield data-base that were established based on self-learning of historical data and computer technology in steelmaking process, a method of yield prediction of alloy elements is studied. To provide support for this method, alloying elements yield prediction software is developed to realize the rapid and intuitive site operation guidance, and to realize the precise control of dosage of alloy material.

Mar 1, 2017

By Caryn Wendt, Donna Post Guillen, Armando McDonald, Erik R. Coats, Chaston Ellis, Kevin Feris

Dairy operations constitute ~2.5% of annual U.S. greenhouse gas (GHG) emissions, making dairies one of the largest sources of industrial GHG emissions. We are developing a novel, integrated system to achieve a net reduction in dairy GHGs while producing value-added materials and products. This integrated manure-to-commodities system converts dairy manure to bioenergy, sequesters carbon by converting volatile fatty acid-rich fermenter supernatant to bioplastics, and utilizes anaerobic digester (AD) and polyhydroxyalkanoate (PHA) reactor effluents to produce algae that can be harvested and internally recycled to enhance PHA production and sequester carbon. A decision-making tool is being developed for the integrated system that quantifies net GHG reduction, carbon sequestration, nutrient management and economics.

Jan 1, 2016

By Tracy Lucas, Ian Hamill

"Issues of importance in the area of continuous casting centre around product quality. This can be affected by particle inclusions transported into the mould from upstream processes and by draw-down of particles from the meniscus. Turbulence of the meniscus can increase the latter and is also detrimental to product surface quality.Suitably validated Computational Fluid Dynamics (CFD) modelling can provide the operator with an efficient tool with which to investigate the effects of changes to the design and operation of the caster and associated plant.In this paper, examples are presented of the use of the CFD software, CFX, to simulate:•,free-surface shape and turbulence in the mould using deforming meshes•,solidification in the mould using a fixed-grid, source-based method•,argon gas injection through a submerged entry nozzle using a full multiphase model•,inclusion motion and removal in tundishes using an algebraic slip model.The CFD simulations of the free surface shape are complemented by detailed Particle Image Velocimetry measurements performed on a full-size water model of a thin-slab mould and upper strand. Close agreement is demonstrated between the predictions and experiments."

Jan 1, 1999

By Ben Bowman

For certain ferroalloy furnaces, such as ferrochrome or ferromanganese, there is still doubt about the mechanisms operating under the electrode tips. In this paper a model is built that does not call upon an arc. The medium is best described as an electrically conducting slurry, a mixture of liquids, solids and gas. There are two sources of propulsion, the Lorentz force within the conducting part and buoyancy generated by CO bubbles, creating two opposed poloidal circulation loops, downward below the electrode axis and upward further out.

Jan 1, 2014

By R. J. St. Eloi

The Kidd Creek Copper Smelter has been expanded from its original design of 59,000 tonnes of copper per year to over 120,000 tonnes per year .. Modifications to the process gas handling system and acid plant have been made to accommodate this higher production rate and to .generally optimize the operation. The gas handling system associated with the continuous smelting process is discussed in terms of boiler accretions and modifications to minimize their impact on operations; design changes to effect reductions in high pressure drop duct configurations; material changes to overcome corrosion and plant additions to &apos;improve gas cleaning capability. The acid plant is reviewed with references to changes made to accommodate the increased S02 gas strength resulting from the higher smelting rates;

Jan 1, 1992

By Shiju Zhang, Yongnian Dai, Songli Liu, Wenhui Ma

The BaZrO3 and CaO-doped BaZrO3 ceramics were fabricated at 1750 °C for melting the Ti2Ni alloys, respectively. Employing XRD, OM and SEM, the influence of CaO on the composition of BaZrO3 and the interaction between the BaZrO3 ceramic and titanium alloy was investigated. The results showed that the CaO doped BaZrO3 was consisted of CaO and Ba 1−xCaxZrO3. The grain on the surface of BaZrO3 ceramic was loose after melting, and the thermodynamic analysis indicated that the dissolution-erosion was responsible for the interaction mechanism. An amount of BaZrO 3 refractory was attached to the Ti2Ni alloy bottom after the alloy was cooled. However, no refractory was found on the bottom of Ti2Ni alloy, which was cooled down on the CaO doped BaZrO3 ceramic. CaO additive can effectively reduce the interaction between the BaZrO3 refractory and the titanium melt, indicating that it was a very promising refractory for preparing the titanium alloy.

Mar 1, 2018

By Xiaoyan Xiang, Wenqiang Yang, Wentang Xia

Magnesium aluminate spinel is widely used in the metallurgical industry as refractory material, however, natural magnesium aluminate spinel is rare and most of the magnesium aluminate spinel is synthetic. The traditional synthesis of magnesium aluminate spinel often needs high temperature, which leads to more energyconsumption. In this article, solid phase sintering process was employed to synthesize magnesium aluminate spinel, in which, magnesium and aluminum oxide were used as raw materials and magnesium and aluminum powder were used as composite additives. The mass ratio of magnesium and aluminum on the effect of synthesis of magnesium aluminate spinel and the characteristic of the synthesis at different temperature and time was discussed. Experiment found that the synthesis temperature was observably lowered when the addition of magnesium and aluminum was 2.0% and 1.0% respectively.

Jan 1, 2016

By Yuan She, Qihang Liu, Keng Wu, Hailiang Ren

By observing different coal char’s microstructures and microscopic morphologies during the coking process, the characteristics of COREX coal char’s microstructure and properties were analyzed. MCRI and MCSR were used to respectively describe the reactivity and the strength after reaction of coal char, with those of BF’s coke for reference, and then the physical meaning of MCRI and MCSR were given. MCRI and MCSR were determined by the composition of coal char. For the two kinds of COREX coal, the formula to forecast the hot performance of coal char was set up by making a multiple linear regression between the hot performance and microstructure of the coal char at 1100℃, and the predictive values of coal char’s hot performance at 600℃, 800℃ and 1000℃ coincided well with the measured values.

Jan 1, 2015

By R. L. Player

"The Copper Isasmelt process has been developed over the past 15 years by Mount Isa Mines Limited (MIM) and the Commonwealth Scientific and Industrial Research Organisation (CSIRO). The first two commercial plants were commissioned in mid 1992.The results of four heat balances on the Mount Isa plant are presented. At a smelting rate of 98 t/hr of chalcopyrite concentrate plus 14 t/hr reverts, the total heat generated was -91MW. Approximately 39% of this energy came from coal, while 50% of the energy reported to the process waste gas. To a first approximation the furnace is near chemical equilibrium.The impurity distribution in the Mount Isa plant was presented. Approximately 91 % As, 85% Cd, 75% Bi, 68% Zn, 60% Sb and Tl, 45% Pb and 30% Te in concentrate was eliminated from the matte.The ""bubble"" frequency of the gas cavity below the foot of the lance was measured at -2. 1Hz. Side bands displaced by -l.lHz modulated the bubble frequency. This was consistent with radial gravity wave motion in the slag bath. The two processes, gas bubbling and wave motion appeared to be coupled together; the bubble frequency was twice the slop wave frequency. IntroductionCopper Isasmelt has been developed over the past 15 years by Mount Isa Mines Limited and the Commonwealth Scientific and Industrial Research Organisation. The process is based on the Sirosmelt lance, invented by researchers at the then Division of Mineral"" and ProcessEngineering ofCSIRO in 1973.The first two commercial scale copper furnaces were commissioned at Mount Isa and the Cyprus Miami Mining Corporation smelter at Miami, Arizona in August and June 1992 respectively.The process concept, the history of the development, and the Mount Isa plant have been described (1, 2, 3).This paper sununarises heat balances obtained on the furnace, the impurity distribution among the output streams and lance injection characteristics."

Jan 1, 1996

By Young-Geun Park

A new decarburization model for the RH system was constructed for calculating the decarburization reaction using a three-dimensional fluid dynamics program. The entire fluid flow in the RH process was calculated by evaluating the shape and volume of the plume zone, formed by Ar gas blown through multiple nozzles on the wall of the snorkel. On the basis of this fluid flow, the decarburizaiton reaction was calculated through establishing the decarburization reaction model, which considers the thermodynamics, reaction kinetics, and the decarburization sites (Ar bubble surface, bath surface, and the CO bubble fomtation at inner sites). The results from this model were compared with a real RH operation results with good agreement. Because it is possible to predict the carbon concentration at various conditions using this model, it may be useful in increasing the decarburizaiton rate. Key words : RH process, plume zone, decarburization, Ar bubble surface, bath surface, inner site, circulation flow rate.

Jan 1, 2001