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By Patrick R. Taylor

Iron phosphate glasses are promising host matrices for vitrifying actinide rich nuclear wastes materials because of their high solubility of actinide oxides, high chemical durability, and relatively low melting temperatures. An iron phosphate waste form was developed at the University of Missouri-Rolla. The structure and property of the waste form were well characterized by materials techniques. However, to scale the process and advance it to commercial viability, it is necessary to understand the processing parameters, such as the partitioning of waste elements and the viscosity as a function of temperature. Viscosity of 40 Fe203 - 60 P205 mole % iron phosphate melts (prepared with phosphorous pentoxide and ferric oxide) at 1000-1200 C was measured by the rotating-spindle method. It was discovered that this fluid has non-Newtonian behavior. Experiments were performed to study flow properties following the Standard Test methods for Rheological Properties of Non-Newtonian Materials by Rotational (Brookfield) Viscometer (ASTM D 2196-86). Samples prepared using ammonium phosphate and ferric oxide showed Newtonian behavior and the temperature dependence of the viscosity was studied over the range of 1000 to 1200 degrees C. The difference in flow behavior between the two fluids was analyzed in terms of preparation conditions and variation in the final composition and phases. The partitioning behavior of waste elements in the iron phosphate glass was studied by melting in a high temperature furnace and JCP analysis. The experimental results show that the solubility of Ce and Sr in phosphate glasses is significantly higher than the solubility associated with borosilicate glasses. This strengthens the conclusion that iron phosphate may be a viable alternative to borosilicate glass for immobilization of high heavy-metal-content wastes and actinide rich wastes.

Jan 1, 2002

By J. M. Demarthe

The recovery of minor metals from zinc concentrates is dependent on the process used for their treatment. The behaviour of gennanium and indium in pyrometallurgical processes such as the Imperial Smelting furnace or the cupola furnace is of practical importance. The .Anaconda process for the treatment of zinc leach residues is not well suited to the recovery of valuable minor metals, and new technologies must be studied. In this regard, a solvent extraction process, using Kelex 100, developed by Minenet Recherche for the recovery of gennanium from dilute sulphate leach solutions is described. Also, new hydranetallurgical techniques in chloride media can be applied to the purification and concentration of minor metals depending on the stability of their chloro-complexes and the valency of associated inpurities. A synthesis of methods is proposed to address the problems related to the recovery of valuable minor metals in the zinc industry.

Jan 1, 1990

By John J. Mazza

Treatability studies were performed to determine the effectiveness of two commercially available treatment methods (solvent extraction and thermal desorption) for the removal of PCBs and PAHs from contaminated dredged riverbed sediments. The solvent extraction method evaluated was the B.E.S.T. process which extracts the contaminants with triethylamine. The thermal desorption method utilized was the ATP process which desorbs the contaminants at elevated temperature in an anaerobic atmosphere. A description of both methods and. an evaluation of the treatability study results is provided. Each treatment method was used to treat two separate samples (high and low concentration) from the site. Overall, both methods proved to be very effective with solvent extraction achieving 98% removal of both PCBs and PAHs and thermal desorption achieving better than 99% removal of both the PCBs and PAHs from the high concentration sample. Both solvent extraction and thermal desorption achieved greater than 99% removals of PCBs and PAHs from the low concentration sample. Vendor cost estimates for full scale treatment were roughly equivalent. The primary differences between the two methods lies in the realm of permitting, operational requirements, and emission concerns.

Jan 1, 1994

By Liwen Hu, Jianxun Song, Hongmin Zhu, Qiuyu Wang, Shuqiang Jiao

The subchloride titanium was prepared by sponge titanium and titanium tetrachloride in the CaCl2 at 1173 K. The species were detected are mainly titanium dichloride, and the average valent in the melt are 2.05. The accurate equilibrium constants were obtained for the reaction 3Ti2+ = 2Ti3++Ti after the accurate activities of titanium chloride were evaluated with emf method, and the observed deviations from ideal behavior are discussed.

Jan 1, 2015

By Cui Wang, Qian Li, Kexin Jiao, Haibin Zuo, Jianliang Zhang

Abstract：A rational cooling water system is the assurance for long campaign life of blast furnace．In the paper, the heat transfer of different furnace period and different furnace condition based on the water quality characteristics were analysed, and the reason of the heat flux over the normal from the hydrodynamics was analysed. The results showed that, the vapour-film and scale existence significantly influenced the hearth heat transfer, which accelerated the brick lining erosion. The water dynamic characteristics of the parallel inner pipe or among the pipes were the main reason for the abnormal heat flux and film boiling. As to the reasonable cooling water flow, the gas film and the scale should be controlled and the energy saving should be considered.

Jan 1, 2015

By Jun Miao, Kang Liu, Jilai Xue, Jun Zhu

CO2 emissions must be reduced by at least 50 % by 2050, and hence the technical solutions to capture and convert CO2 into value–added products should be considered. A Cobalt(III) Schiff base complex (Salen–Co(III)) has been investigated as a catalyst for synthesis of cyclic carbonate from CO2 and epichlorohydrin(ECH) with tetrabutylammonium bromide (TBAB) as co–catalyst. To recover Salen–Co(III) for the next cycling operation, it was immobilized onto zeolite 13X through excessive impregnation method. The immobilized catalyst was characterized using XRD, SEM, BET and ICP–AES techniques. Catalytic tests showed that yield of cyclic carbonate reached 90 % using 0.5 mol % Salen–Co(III) at ambient conditions. The immobilized Salen–Co(III) exhibited better catalytic activity than the homogenous one when used at the first cycle, but the yield decreased by some 20 % after five cycles.

Jan 1, 2015

By Jing Zhan, Gui Li, Wei-feng Li, Li-Hua Jiang, Chuan-fu Zhang, Jian-yang Hwang

Thermodynamics analysis for processing the charge with lead concentrate and lead sulfate-containing materials in bottom blowing smelting furnace was conducted. The results show that the technology of large-scale processing PbSO4- containing materials with PbS concentrate in bottom blowing furnace under the condition of using high-iron slag type, batch heat supplement, high temperature and rich oxygen is thermodynamically feasible. The exploration test and industrial experiment confirm the results. When S content in mixed ore is 16~17% with coke foam content of about 5%, the lead paste amount can be increased up to 40%.

Jan 1, 2015

By Flavio Begazo, William A. Enrico

"Southern Peru Copper Corporation's Ilo Refinery, the largest in Peru, began operations in 1975 with a production capacity of 165,000 stpy. Southern Peru bought the Refinery from the state owned Minero Peru SA on June 1, 1994.The Refinery processes blister from Southern Peru's I/o Smelter. Blister copper is processed in an anode plant equipped with two 365 st tilting reverberatory furnaces, a 26 mold casting wheel and an anode press machine. Copper is electrorefined in a tank house equipped with 768 commercial cells, 44 stripper cells, and 40 liberator cells, utilizing two electrolyte circuits and a 21,000 Ampere rectifier.During 1989 through 1994 a program for improving productivity was carried out by increasing the number of cells and increasing current density to the total rectifier capacity. As a result, a capacity 215,000 stpy of refined copper, 2 million tr. oz silver and 6,000 tr. oz gold per year was achieved. In 1994 Southern Peru announced plans to increase capacity to 250,000 stpy of cathode with a US$ 18 million investment and a US$ 2 million investment in environmental improvement projects, as part of the purchase agreement with the Peruvian government.This paper outlines the scope of the SPCC lio Refinery modernization and environmental program. It describes the implementation of the Electrolytic Plant expansion based on instaliation of polymer concrete cells, a new rectifier, a new selenium roaster and a Precious Metal Plant upgrades."

Jan 1, 1997

By Thor Pedersen

Elkem's technologies for the processing of waste materials, dusts, sludges and other residues, are based on the use of their Multi-Purpose Furnace as the primary processing component. The Multi-Purpose Furnace? is an electric slag resistance reduction furnace equipped with a hot media, Modular Freeze Lining and Elkem's proprietary, air tight electrode seals. The oil cooled? freeze lining allows specific heat fluxes 2 to 3 times higher than furnaces lined with conventional refractory. Reduction activities taking place within the furnace are free from the reoxidation potential of infiltrated air as Elkem's electrode seals are positively gas tight. Small quantities of highly concentrated off gas of controlled composition are produced to suit the requirements of downstream processing. The high electrical thermal efficiency achieved by generating heat within the slag itself, combined with the ability to operate at high melting rates and intense power density, makes the Multi-Purpose Furnace 9 an unique implement for the design of furnace products. These characteristics are utilized in the processing example cited, "Elkem's EAF Dust Processing Technology", which combines two proven technologies in an economically feasible system for the recovery of contained metal values from K061 wastes at the same time producing a disposable slag product. The portion of the example dealing with the condensation of zinc was prepared with the assistance of Imperial Smelting Processes, Limited of Bristol, England with whom Elkem has a non- exclusive license.

Jan 1, 1990

By S. V. Cherty

The utilization of natural gas in non-ferrous industries during smelting and refining stages of copper , aluminum, zinc and lead was studied. The total amount of nonelectrical energy consumed in the production of zinc, copper, lead and aluminium, are 96.5% ,93%,92%, and 6 % respectively. It is calculated that 9.45 wt %of air of stoichiometric amount can be substituted by natural gas to the total air input in the nonelectrical energy utilization processes. The results showed that the non electrical energy may be substituted to an amount of 71 % ,52 % ,35 % ,32 % ,and 26% ,in the production of lead, aluminium (plates, foils) copper, aluminium, zinc, respectivelly. Similar calculations are carried out in terms of energy in Btu for the total production of non-ferrous metals in the U.S. It shows that 51.866~106 millions of Btu of nonelectrical energy can be substituted by 54.58~106 cu. ft of natural gas. Finally, the substitution of non electrical energy in terms of equivalent coal energy is discussed. 1t is shown that total non electrical energy is equal to 1.852 million tones of coal .If this 1.852 million tones of coal is replaced by natural gas, a total savings of 22.14 million dollars are achieved. The total or partial substitution of coal by the natural gas in the existing industrial processes and modification of redesigning the processes is discussed.

Jan 1, 1993

By Kandipati Sreenivasarao

Ion and precipitate flotation involve adding an appropriate collector to aqueous solutions containing metal ions, to form hydrophobic metal-collector complexes or precipitates that can be removed by flotation. With a better fundamental understanding of the effects of physical, engineering and chemical parameters on the performance, ion and precipitate flotation techniques could usefully complement techniques now available for removing metal ions from dilute solutions. The removal of Cu(II), Pb(II), Cd(II), Cr(III) and Cr(V1) has been studied, using different types of collector, according to the nature of the metal-bearing species. The effects of collector/metal ion ratio, and solution and froth height on the flotation kinetics, bubble coverage by the metal-collector complex, recovery of metal and effluent quality are reported. The observed behavior is related to the solubility products of the metal-collector complexes, which were also determined.

Jan 1, 1994

By F. A. Myzenkov

The technology developed by the authors uses new methods for raw material smelting in electric furnaces, a new autogenous method and apparatus for subliming smelting for antimony trioxide production and separation of antimony and gold. Concentrate produced from the ore deposits in Yakutia has the following average contents of main constituents, % by weight: 29.4 Sb, 1.2 Fe, 13.1 S, 40.0 SiO2, 0.2 As, 2.6 CaO and 45 g/t of Au. Unlike the technology used abroad a new autogenous method makes it possible to increase considerably specific capacity and reduce gold losses with antimony trioxide by several times. At the same time mineralogical composition of trioxide has improved considerably ? it has mainly a cubic base with prevalence of senarmontite. The content of a main component (Sb2O3) in the final product has increased from 99.0% up to 99.6% which means better quality and makes it suitable for use in special technologies. Despite a lower antimony content of the concentrate (29.4% as compared with over 33% as common in the world practice), an antimony recovery of 85.3% into a commercial-grade product has been achieved, as well as a gold recovery of 96.65% into a gold-antimony alloy. The technology for processing gold-antimony materials developed and introduced at the Ryaztsvetmet plant is unique in the world with respect to gold recoveries.

Jan 1, 2006

By Yuanbo Zhang, Guanghui Li, Zhenyu Fan, Tao Jiang, Xiaohui Fan

"Iron ore sintering process is the main source of SO2 generated in the steel industry, of which the discharge amount of SO2 emission accounts for about 60% of the total. Aiming at the features of sintering flue gases and existing problems during the flue gas desulphurization, a technical route of flue gas circulation sintering (FGCS) for iron ores has been put forward. Under the simulated experimental conditions, effects of FGCS process on the main output and quality indexes and SO2 emission rule are researched using simulating flue gases. Compared the novel FGCS with conventional sintering process, SO2 in the final sintering flue gas is obviously enriched and the total exhaust gases can be reduced evidently. The decreasing of oxygen content in circulating gases has bad effect on the sintering indexes. Increasing the oxygen potential is beneficial to obtain high quality sinters. This investigation shows that the FGCS process is promising.IntroductionSteel is a kind of essential material for modern society, but steel-making process is characterized by high energy-consumption and emission as well as heavy environmental pollution. Chinese steel industry has developed rapidly in the last decade, and the environmental problem caused by ironmaking and steelmaking have also aroused the greatest concern, especially the atmospheric pollution caused by SO2, CO2, etc. Iron ore sintering process is the main source of SO2 generated in the steel industry, of which the discharge amount of SO2 emission accounts for about 60 % of the total. The development of the desulfurization process for sintering flue gases to reduce SO2 emission in sintering process is not only the requirements of sustainable development but also the most important environmental tasks for steel industry [1-5]."

Jan 1, 2011

By Fuming Wang, Xi Chen, Shuai Liu, Changrong Li, Dan Wu, Yaxu Zheng

The effects of B content and austenitizing temperature on hardenability and toughness of Cr–Mo alloy steel have been studied. The results show that the hardenability is deteriorated with increasing B content and austenitizing temperature. With increasing temperature, more and more B containing particles were dissolved in austenite and increase the amount of B atoms segregating at grain boundaries. Moreover, the coarsening grains reduce area of grain boundaries and also increase the amount of B atoms at unit grain boundary, excessive B atoms segregating at grain boundaries promotes precipitation of M2B, which accelerates ferrite nucleation and reduces hardenability. The main elements in M2B phase are Fe, Cr, Mo and B. The B atoms segregating at grain boundaries during austenitizing promote precipitation of M2B during tempering which deteriorate toughness significantly.

Mar 1, 2018

By P. Louis

Although cobalt is known and used for its hardness and wear resistance, ductile cobalt can be obtained by electrolysis in chloride solutions, under the following conditions : pH : 1.5 - 2, Co++ : 30 - 60 g/l, current density : 100 - 500 A/m2, temperature 40 - 70°C. No explanation was found for the ductility of the deposit under these conditions. Indeed the ductile P (FCC) cobalt and the hydrogen contents in the cobalt deposits are nearly the same as those obtained in a sulfate media, which gives brittle depo¬sits under equivalent electrolysis conditions. Malleable cobalt sheets can be easily obtained under the proposed conditions which could lead to new applications for cobalt.

Jan 1, 1988

By Neil Rowlands

Particle liberation studies are commonly used in the determination of the proportion of locked and liberated phases in ground ores at various stages of mineral processing. These studies may range from a qualitative assessment of a polished specimen in an optical microscope to a full quantitative analysis of the liberation characteristics of fine grained complex sulfide ores using scanning electron microscopy and high level image analysis. However, the conversion of quantitative data to meaningful information on a mill operations level is by no means a simple task. This paper reviews the errors inherent in the SEM/Image Analysis technique and looks at the various methods available to minimize errors in data collection.

Jan 1, 1992

By Steven M. Puricelli

Sulfuric acid plants associated with smelters, have historically been an overworked and often neglected pollution control device. They could do little more than manage the wide fluctuations in gas flow and SO2 strength from the smelter. With the introduction of flash smelting, the picture began to change, but the fluctuating batch converters continued to dictate acid plant design. More recently, the commercial use of continuous converting processes utilizing high levels of oxygen enrichment has dramatically upgraded the SO2 strength and stabilized the gas flow to the acid plant. The SO2 gas now issues continuously and at concentrations that allow for compact and, cost effective acid plants. Relieved of the burden of excessive dilution air, the heats of reaction can also be recovered as medium pressure steam and used to drive a generator, making the acid plant a net producer of power and a valuable asset to balance sheets. This concept was put into practice at the Kennecott Utah Copper Corporation smelter modernization project, located in Salt Lake City, Utah. The new acid plant, which was commissioned in June of 1995, is a sophisticated, low environmental impact, energy producing plant, worthy of review. This paper examines the key features of this acid plant, such as controlling its tail gas, by catalysis alone, to an environmentally friendly, 100 ppm of SO2, while feeding the acid plant converter with an efficient 14% SO2. The acid plant is also a prudent steward of energy resources, recovering 220,000 lb/hr of 140 psig steam from process heat which is used to generate a substantial 20 MW of gross power. Also discussed will be some of the ongoing issues, such as handling of selenium and fluorine in the gas cleaning sections, as well as a review of some. of the problems that were identified and resolved. Today's modem acid plants, by necessity, are becoming a producer of quality, valuable products, making the acid plant an asset and not a liability. Plants like Kennecott are already gaining wider acceptance and are expected to be the vision of the future.

Jan 1, 1998

By Sacha Neven

Submerged lance technologies combine high intensity processing characterized by rapid mixing and reaction rates using a simple reactor design. The Isasmelt technology uses a central submerged lance to inject oxygen-enriched air and fuel into a bath thus creating large gas bubbles and intensive turbulence and splash. The lance is equipped with swirlers to increase gas velocity and heat transfer. This enables the formation of a frozen slag layer on the lance which protects it from the aggressive environment. Water models as well as high temperature reactors were used to validate the Davidson-Schiiler model on bubbling. Frequencies and pressure amplitudes were measured in a wide range of gas flow rates: from m3/sec using a water model to more than 30 m3/sec in an industrial process. Agreement with the model was satisfactory. The experiments however also clearly showed that cross-flow and bubble wake induce slightly higher frequencies. No influence of the use of swirlers on the bubbling frequency was observed in the water models.

Jan 1, 2002

By Yutaka Shiraishi

Two methods were developed to measure the viscosity of the slag from the glassy to the liquid states in an ascending temperature process. The first method employs rotating parallel plates within which is placed a solid cylindrical sample in line with a sphere. The second method uses a tube which is pushed into a sample held in a rotating crucible. Both methods were tested using standard glasses, including boron trioxide and NBS standard glass #711. The main difference between these two methods is in sample preparation. Comparative measurements between two methods were performed using a sodium boro-disilicate glass containing 5%mol of alumina. The results showed good agreement in the mid-range of glassy viscosities, 105 to to7 Pa.s. In the liquid state, there were no significant differences between the two methods.

Jan 1, 2003

By Mark Jolly, Nasim Soleimanian

"During the last 20 years CFD (Computational Fluid Dynamics) has been used as a tool to aid furnace designers and manufacturers to improve energy efficiency and effectiveness of glass furnaces. However as the models are maturing the effect of feeding equipment used to push the raw material into the furnace has not been included in the process models. This paper investigates the effects of batch pattern in the melt space caused by charging equipment on the energy efficiency of the furnace focusing on the melting zone. A simple batch patterns sensitivity study has been performed using purpose built software (Glass Furnace Model-GFM). It is concluded that in order to further reduce the energy consumption of the furnace it is necessary to model the batch charging process in more detail to find more opportunities for improvement.Introduction Glass manufacturing is a conservative industry which applies to all the four major segments (float glass, container glass, fiberglass, and specialty glasses). Risks due to the high capital investment, very long service life of the furnaces, and the demand for high performance and quality from the outset translates into evolutionary progress rather than revolutionary. The main problem facing glass manufacturers are the financial cost of manufacture, its impact on the environment, and mounting pressure imposed by the authorities for greener manufacturing and reduction in emissions.The main energy intensive activities involved in continuous glass manufacturing are: the need for high temperature to create and maintain the viscous flow, homogenisation of glass melt (melt residence time), and maintaining the two to achieve continuous output of glass at the right quality. The high temperature and long duration of homogenisation has resulted in the design oflarge furnaces, which have high energy consumption, low specific performance, and high C02 emissions. As an example in the container glass sector the most efficient furnace has a specific primary energy consumption of 3.8 GJ /tonne of glass at a level of 50% cullet in the batch. Even very small improvements in efficiency by optimising operation would have a high impact [1-14]. Given the conservative nature of the industry and the costs involved in experimental data gathering, CFD modeling of the process has been used extensively during last two decades to not only improve our understanding of the process but also as a tool in predicting possible optimisation windows, e.g. Glass Furnace Model ( GFM), a commercially available piece of software that has been developed to optimise furnace operation."

Jan 1, 2013