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By Larry Southwick

This Peirce-Smith Converting Centennial symposium is celebrating the contributions of two men, William Peirce and E.A.C. Smith, in advancing technology allowing the copper industry to realize its full potential. However, theirs is representative of a larger story: New, simpler technology releasing the stranglehold of older, more complicated technology, new developments in vessel configuration and design finding alternate routes around dead ends in operability, advances in technique and concepts removing roadblocks of cycle time and capacity, and overall innovation opening up vast new reserves around the world to those companies willing to embrace those improvements. Our story is also one of personalities, stubborn smeltermen versus the innovators, those inside the industry versus those from outside. It is a story of an initial borrowing from the steel industry, but also Peirce and Smith, from the refining end of the copper business, taking the ideas of Baggaley from Pittsburgh’s steel and airbrake industry, who built on what Hollway, Manhès and David, Douglas, and others had done in smelter tests, further to compete with the previous primacy and closely held expertise of the copper smeltermen in Wales. These advances have been well recorded in photographs taken over the last 150 years. A number were submitted especially for this symposium. Many others were published in the mining and metallurgy press of the times. Several mining schools also retained copies of photos either taken during field trips, or donated to the school by alumni and operating companies. This presentation will provide a selection and discussion from these sources of “converters in action”, describing the various designs, operations and developments depicted. The focus here will be on the first roughly 60 years of copper converter development, from Bessemer’s days at the dawn of this new idea, up to and slightly past the time of initial adoption of Peirce and Smith’s designs.

Jan 1, 2009

By Sven Reutzel

Investigations show that Co-based melts embedded by glass flux in a crucible can be under- cooled nearly as strong as samples processed containerlessly by electromagnetic levitation. This allows to measure magnetic susceptibility on undercooled melts while combining the use of a Faraday-balance and undercooling technique. The magnetic susceptibility of Co and Co-based alloys (such as Co-Pd and Co-Cu) is investigated as a function of temperature from superheated to undercooled state. This is done by measuring the change of magnetic force F, on a sample in a constant magnetic field Bo and an additional gradient field by means of a Faraday-balance. When liquid Co-based alloys are undercooled the magnetisation steeply rises if temperature approaches the Curie temperature. The magnetisation is measured for some Co-based alloys in liquid state as a function of alloy system and its concentration. The results show that the magnetic susceptibility of the liquid undercooled samples follows a Curie-Weiss behaviour, from which Curie temperature and magnetic moments for the liquid state are inferred.

Jan 1, 2002

By Yotamu Stephen Rainford Hara

"The aim of our work is to investigate a low energy and clean route for the recovery of copper and cobalt from complex sulphide mineral concentrates. The mineral concentrates were roasted in air, in the presence of CaO (MS + CaO + 202 =MO+ CaS04) at temperatures below 973K. The roasted products containing CuO, CoO and Fe203 were carbothermically reduced at 1073K within an hour to preferentially reduce copper and cobalt. The kinetics of reactions were studied using the thermogravimetric technique and by characterisation ofreaction products using the XRDSEM-EDX techniques. The effects of MS:CaO ratio, roasting temperatures and physical nature of the mineral concentrates were analysed. The method for capturing S02 by forming CaS04 was analysed for reuse in the process. The energy balance for the above process is compared with that of conventional continuous smelting/converting process.1.0 IntroductionCopper sulphide mineral concentrates from Zambia contains substantial amouot of cobalt. The cobalt metal content in the concentrates ranges between 0.7 and 2 % weight, which corresponds to 3 and 9 % weight copper, based on the spot price of copper ($7 386/tone) and cobalt ($31 000/tone). Although the traditional approach using a combination of roasting-leaching-electrowining steps can be applied to recover copper and cobalt from sulphide mineral concentrates [1-4], there are two major draw backs of the traditional process: (i) the S02 emitted during roasting is too lean for economical conversion for sulphuric acid manufacture, which causes serious environmental pollution. (ii) silver and gold which are normally present in the sulphide concentrates are lost out [5] because they are not leachable by H2S04 or HCl which are the common leachants. The above two problems have been overcome by adopting flash smelting in which a rich S02 gas above 20% is produced [1, 5] and successfully converted into sulphuric acid. The precious metals tend to partition to blister copper and recovered during refming. However, nearly all cobalt is lost into the slag phase uoder oxidising condition which prevails during flash smelting. It is important to note that the cobalt content in the slag can be up to 2.6 % weight [6]. The recovery of cobalt from the slag is a process which requires huge amouot of energy since the slag is smelted above 1873K [6]. With a view of minimising the amouot of energy and S02 emission during metal recovery, our investigation involves roasting the sulphide concentrates in the presence of lime and reducing the roasted samples with carbon."

Jan 1, 2013

By Ryszard Prajsnar

During copper production in shaft and flash smelting processes at KGHM Polska Miedz S.A., lead bearing material of sulfide, sulfate, and oxide character is generated in forms such as slime from shaft furnace gas handling systems, converter dusts, and dusts from an electric furnace for copper removal from flash smelting slag. These materials are polymetallic concentrates of Pb, Zn, and Cu, with As, Cl, and Cd as impurities. Shaft furnace slime, containing. about 50% PbS and 15% bituminous substances, is the main lead-bearing material. At the Glogów copper mill, a new plant was commissioned in June 2001 to process 80,000 tonnes per year of lead bearing materials to produce 26,000 tonnes per year of crude lead. The plant consists of a feed conditioning system, three (3) rotary rocking furnaces with a capacity of sixteen (16) tonnes of lead feed fired with natural gas and oxygen-enriched air containing up to 45 vol% O2, and a gas handling system. The gas handling system includes a post-combustion chamber, a gas cooling chamber with Cl neutralization, gas mixing chamber, bag filter, and dry limestone scrubbing system for SO2 removal. The lead-bearing feed is smelted with five (5) wt% Na2CO3 and thirteen (13) wt% iron scrap at a temperature of 950 to 1050°C for three (3) hours. The smelting process consists of four (4) stages; feed drying, firing of gaseous hydrocarbons and solid coal from the feed, lead reduction from slag, and separation of molten products. The flow rates of natural gas and oxygen to the burners are controlled to ensure combustion of the bituminous material in the furnace. The process produces crude lead bullion containing (wt%) 0.1 to 0.5% Cu, 0.02 to 0.5% As, 0.05 to 0.07% Bi, 0.1 to 0.5% Sb, and 0.1 to 0.6%Sn. The process also produces a mixture of sodium silicate slag, Fe-Zn-Pb-Cu-S matte, and Fe-As speiss containing (wt%) 5 to 10% Pb, 2 to 6% Cu, 10 to 15% Zn, 1 to 3% As, 10 to 15% S, 0.5 to 3.0% Cl, 2 to 4% K, 4 to 7% Na, 20 to 30% Fe, and 5 to 10% SiO2. The dust is made up of PbO, ZnO, PbSO4, and PbCI2, KCI, and NaCI with a chemical composition (wt%) of 35 to 50% Pb, 5 to 15% Zn, 3 to 6% As, 4 to 8% Cl, 2 to 5% K, and 2 to 5% Na. The construction of the new lead production plant at the Glogów copper mill will process both current lead-bearing materials as well as lead-bearing material that have been stockpiled over the last fifteen (15) years to give a significant improvement in protection of the natural environment.

Jan 1, 2002

By Daniel K. Lindberg, Fiseha Tesfaye

To reduce the use of fossil fuels and increase self-sufficiency in energy, nowadays, there is an increasing interest to produce heat, power and transportation fuels from renewable resources. Solid biomass is one of the most important renewable energy sources for meeting this target. However, fouling, slagging, and corrosion threaten long-term operation availability and costs of biomass power plants. Slags accumulated on the surfaces of superheaters, which decrease thermal efficiency, often constitute a considerable percentage of complex inorganic phases. However, thermodynamic properties of the complex inorganic phases and their combined effect, which will help to deal with the slag related problems during high-temperature biomass combustion processes, are not well known. In the present paper, thermodynamic properties of K-, Ca-, and Na-based inorganic phases and their mixtures under different gas conditions are both critically reviewed and experimentally studied. The obtained results are presented and discussed.

Mar 1, 2017

By Toshiki Kabutomori

In fuel cell powered automobiles, hydrogen is required to be stored in materials that have a hydrogen storage density of over 4 mass%; further, these materials should be capable of supplying hydrogen by using the waste heat from a fuel cell, which is at a temperature of 373 K, in order to match the mileage of gasoline-powered vehicles. A Ti-Cr-V alloy, which exhibits a BCC structure and forms a solid solution, is a promising candidate for onboard hydrogen storage materials. Although it has a large hydrogen storage capacity of over 3.9 mass%, the rechargeable hydrogen capacity is limited to approximately 2.6 mass%. In this study, the effects of fine pulverization of the alloy on PCT (hydrogen pressure-composition-isotherm) characteristics were investigated in order to improve the rechargeable hydrogen storage capacity of the alloy. From the PCT measurements of the finely pulverized samples of the alloy, a plateau in the absorption curve was observed to begin at a hydrogen concentration of 0.5 mass%; further, a rechargeable hydrogen storage capacity of 3.3 mass% was obtained. This was greater than that obtained from the sample that was not finely pulverized, i.e., 2.5 mass%. However, the plateau width in the desorption curve was 2.5 mass%, which was the same as that observed for the sample that was not finely pulverized. The increase in the rechargeable hydrogen capacity during absorption is attributed to the precipitation of the -hydride phase (MH~2) directly from the metal phase (phase). The precipitation of the phase (MH~0.5), which should be formed in low hydrogen concentrations, is suppressed as a result of a possible reduction in the internal defects such as dislocations, vacancies, and grain boundaries by fine pulverization and annealing of the alloy.

Jan 1, 2006

By David G. Dixon, Maziar Eghbalnia

"Gold and silver nanoparticles (NPs) were deposited on pyrite at ambient temperature from colloidal solutions prepared by reduction of hydrogen tetrachloroaurate or silver nitrate by sodium sulfide or sodium tetrahydridoborate. The nanoparticles were characterized using Ultraviolet-Visible (UV-Vis) spectroscopy and the experimental spectra were fitted using Mie - Gans modeling. The modified pyrite was investigated using Electrochemical Impedance Spectroscopy (EIS). Electrodes were prepared from both natural and modified pyrite samples and were modeled using an equivalent circuit (EC) based on the EIS data. The comparison of the results revealed a decrease in charge transfer resistance for the ferric ferrous redox couple associated with the modified pyrite. From this behavior it is concluded that the electronic transport between the nanoparticles and the electrode surface over distances in nanometer scale is enhanced. Nanoparticles below a certain size act as quantum dots due to electronic confmement. Decreased charged transfer resistance at the nanometer scale may be caused by electron transport through tunneling mechanism via quantum dots.IntroductionIn recent years, considerable attention has been focused on the synthesis and study of Metal nanoparticles due to their potential applications in the fields of physics, chemistry, biology, medicine, material science and their interdisciplinary fields[!]. When material is nano-sized, the physical properties deviate markedly from those of bulk material, however, this effect is highly dependent on the particle size, interparticle distance, and morphology of the nanoparticles [2].An extremely small region of space defmed in a semiconductor material in order of nanometers is called a quantum dot, a term coined by Reed [3]. The three dimensional confinement of quantum dots can change properties of the excitons in comparison to free excitons in a bulk material [4]. Nanoparticles behave electronically as zero-dimensional (restricted in all three dimensions) quantum dots when the de Broglie wavelength of the valence electrons and the particle are in the same size range.As Reed [3] explains electrons confined in a plane have no freedom to move the third dimension. Those confined in a quantum wire are only free to move in one dimension, and those confined in a quantum dot are not free in to move in any dimension. An electron inside a cube of material IO nm on a side is confined to a point."

Jan 1, 2012

By Bo Björkman

A controlled dust generation whereby the dust generated would be enriched with specific metals would considerably facilitate the possibilities of recovering metals from such dusts. A basic understanding of the dust forming mechanisms is of fundamental importance to achieve a controlled dust generation. The present study deals with dust formation in a copper converting process. Dust samples collected from various places in the gas cleaning system were characterised for chemical and mineralogical composition using chemical analysis as well as microprobe analysis. Thermodynamic calculations were used to predict the formation of chemically formed dust at various temperatures and amounts of leakage air to the gas system. The results show that a separation of mechanically formed dust. e.g . Si0:2. Cu and chemically formed dust. e.g .? Ph, Zn, As, Bi. could, to some extent, be obtained due to their different particle sizes. A selective condensation of Pb, Zn and As at various temperatures could. according to thermodynamic calculations, he possible at high temperature. A selective condensation of metals requires an airtight gas cleaning system or a gas cleaning system with a limited amount of leakage air in order to maintain the desired temperature level.

Jan 1, 1996

By R. Reed von Gal

The majority of zinc strip produced in the world today is cast on the Hazelett twiri-belt continuous casting machine. Ten of these machines are currently operating worldwide, and one machine is under construction for the People's Republic of China. The caster, which was first patented in 1947, was originally developed for aluminum and copper alloy casting. In the early 1960s, the design was expanded into zinc casting and within ten years the industry had essentially converted from casting and rolling ingots to twin-belt continuous casting with in-line rolling. The casting process employs two parallel, moving. water-cooled belts as the major mold surfaces. Together with two strings of side dam blocks, the design offers a four-sided moving mold which produces a continuous strip or bar. This paper will cover a bit of, the history, as well as the current technology surrounding this high production process for zinc strip production.

Jan 1, 1990

By Albaharna O. T., Argyropoulos S. A.

"This paper describes the development and the implementation of process control in a variety of instruments used in metallurgical laboratories. These instruments are used for different research projects in extractive metallurgy. Hardware and software aspects for this implementation are described and analyzed. Extractive metallurgy applications where process control was .used are presented. IntroductionMicroprocessors are invading almost every area of our lives and are turning up in unexpected applications. A great deal of new equipment which is coming into the market have built- in microprocessor systems. Nevertheless, the area of upgrading existing processes has been slow to develop. There are a variety of reasons for this, and many of these are economic. One of the principal reasons, however, is the general reluctance on the part of many organizations to commit a strong effort to put this new technology into their existing processes.Microprocessor systems developed ""in lab"" are capable of not only measuring thermophysical events which are taking place in metallurgical furnaces, but simultaneously controlling these furnaces. In this paper software and hardware aspects in the implementation of microprocessor control for resistance and for induction furnaces are presented. In addition to this, metallurgical results are given from experiments where this furnace control was applied."

Jan 1, 1989

By Burcu Ertug, Necip Ünlü

"On average, one out of two glass bottles coming on to the market is provided by recycling processes in Europe. Glass recycling has been started by the early of 1970s in Turkey, and the recycling amount has been reached to 70 thousand tons recently, while 4.2 million tons which represents only 25 percent of total glass manufactured, is the amount of glass collected annually for recycling in the world. The glass recycle process basically involves collecting, sorting, then crushing and grinding after which glass cullet is produced as the secondary raw material. Removing of the contaminants from the glass cullet, and then melting are the next steps. In this study, recent developments of 100% recyclable without any deterioration in quality, and never decomposable glass, are discussed detailed in terms of glass production processes.1.IntroductionIn many countries, waste glass constitutes a large proportion of solid wastes, and recycling the glass is a major environmental problem all over the world [1]. Among the diverse types of waste, glass is one of the most valuable recycling materials because it can be revived and recycled completely and hardly decomposes [2]. Between 80% and 85% of the mass output from the worldwide glass industry is either in the form of containers for the food, beverage, and pharmaceutical industries, or flat glass for building construction or for motor vehicle manufacture. Other product segments, whilst only constituting about 15% of the mass output, produce high value technical and consumer products by comparison with container and flat glass [3].In the present study, the recycling of Liquid Crystal Display (LCD), Cathode Ray Tubes (CRT) and Printed Circuit Boards (PCB) were examined. The production of glasses and glass-ceramics from glass cullet, synthesis of different compounds from recycled glass were other subjects of interest. The use of recycled glass for construction industry and using glass as aggregate were emphasized. Finally the recovery of glass fibers were investigated."

Jan 1, 2012

By Zhucheng Huang, Zhikai Liang, Ronghai ZHONG, Lingyun Yi

In this work, research of reduction process was studied by means of rotary kiln (u1.5 m /C215 m) process anatomy in order to provide fine guidance to large-scale operation. It was shown that the average reduction degree of 89.96% and metallization ratio of 85.15% were obtained at the highest temperature of 977°C and total residence time of 90 min. The generation amount of metallic iron in section of temperature higher than 900°C and lower than 900°C was 34.15 and 56.38%, respectively. The section of lower temperature of 830–900 °C played an important role in formation of metallic iron, making it possible for mini-pellet to reduce quickly at lower temperature. Two main tasks were completed for mini-pellets in rotary kiln: the reduction of iron oxides in the range of 15.0–4.5 m as well as migration and bene ficiation of metallic iron, facilitating the subsequent separation of iron and gangue minerals.

Mar 1, 2018

By Jewel A. Gomes

Keywords: Electrocoagulation, arsenic removal, fuel cell, windmill, energy simulation, combined Fe-Al electrode assembly Arsenic contamination of well-water in different countries has caused signs and symptoms of arsenic poisoning. Although several physicochemical treatments are presently used for the removal of arsenic compounds from drinking water, an electrochemical treatment, electrocoagulation, is a promising processing technology and currently is the most efficient (above 99% removal) and environmentally friendly technique, particularly if combined with alternative energy sources. Wind and fuel cell technologies can be considered the most promising developmental clean power sources. We will discuss new insights into the materials processing mechanisms and show the coupling of electrocoagulation with fuel cells and simulated wind energy sources. Different electrocoagulation plate materials were considered, along varied currents from the fuel cell to produce maximum arsenic removal. Coupling these technologies will remove carcinogenic arsenic from water sources, and will exhibit efficient usage of these energy sources by producing pure water for human and agricultural consumption.

Jan 1, 2005

By A. P. I. Popoola, D. O. Okanigbe, A. A. Adeleke

In view of the steady depletion of primary sources of copper and the increased global demand for refined copper, it becomes necessary to explore some secondary sources for possible extraction of copper. The waste copper smelter dust (CSD) is a rich secondary resource for copper as shown by the chemical composition of the South African Palabora coppers smelter plant CSD that assayed 18.02, 13.36, and 3.4 wt% copper, iron and sulphur, respectively. Studies on CSD have focused majorly on either dust characterization or treatment, while hydrometallurgical extraction without pretreatment and with pretreatment using techniques such as oxidative roasting are also considered quite attractive. The challenge of iron dissolution during the leaching stage in these processes necessitates adequate purification of the leach liquor before the extraction of the metal as nano-particles. Hence, this review examined the theories relating to the characterization and treatment of CSD for copper recovery as nanoparticles; with factors having a bearing on the treatment process such as kinetics considered with the aim of providing scientific basis for the research.

Mar 1, 2017

By Leonardo Gonçalves Pedroti, Fernando de Paula Cardoso, Beatryz Cardoso Mendes, Afonso Ramos Garcez de Azevedo

This work aims to produce paints using granite waste, as a pigment, and compare their performance to soil pigments based paints, in terms of hiding power and abrasion resistance. Initially, the residue and soils were physically, mineralogically and morphologically characterized. For the production of the paint samples, an experimental model was defined, based on the variation of the proportions of pigment and resin. The proportion of water varied in each sample, in order to maintain the viscosity within a range considered ideal for application. Sequentially, tests were done to determine the hiding power and abrasion resistance of inks. It was found that, in comparison to soil paints, the granite residue paints presented greater hiding power. This result can be explained by the characteristics of the granite residue, which allowed a high nonvolatile content in the mixtures. With respect to abrasion resistance, granite residue paints showed less resistance than soil paints, possibly due to the granulometry of the residue that resulted in a greater roughness of film. In addition, none ink sample satisfied the minimum specifications prescribed in the Brazilian standards for hiding power and abrasion resistance, at the same time. This means that these inks, when used, will require more repair and repainting over time than conventional paints.

Mar 1, 2018

By Lassi Klemettinen

For better understanding and maximal value utilization of the WEEE smelting process, the behavior and distribution of different trace elements must be known. In this study, the behavior of nickel as a trace element was studied in an equilibrium system with metallic copper—spinel saturated iron silicate slag (with 3 wt-% K2O)—iron aluminous spinel—gas. The experiments were conducted in alumina crucibles at 1300 °C, in oxygen pressure range of 10−10–10−5 atm. A time series of 15–60 min experiments was also conducted for investigating the formation rate of the primary spinel phase in the system. The results show that the distribution coefficient of nickel between metallic copper and liquid slag changes from approximately 70 to 0.4 along the increasing oxygen pressure range. In addition, a significant part of the nickel deports into the spinel phase. The spinel formation was investigated based on composition analysis results and visual observations from SEM-images.

By J. P. Schde

The authors deal with nickel production and usage patterns, nickel's first-use and end-use, examples of nickel applications in modern technology, e.g., energy generation and conservation, environmental protection, the oil and gas industry, construction and machinery, food production, conservation and distribution, consumer durables and the like. A special section of the paper is devoted to new applications of nickel in the electronic industry, modern corrosion control and the building and construction industries. The need to defend traditional markets for nickel while striving to find new applications, is also stressed.

Jan 1, 1988

By Ahmet Haxhiaj, Bajram Haxhiaj

Based on the placement of lead and its consumption in industry branches, the paper deals with the composition of lead in the massive of Kopaonik. Removal, tenuity and grinding of galenit. The paper in particular treats the flotation process, and also treats physico-chemical bases of reagents in the process, as well as decanting, drying, filtering and storage of concentrates. Verification of the chemical composition of Pb concentrates with Pb, Zn, Bi, As, Sb, In, Au, Ag, etc. It is special that in Kopaonik massive the ratio of Pb: Zn composition is 1.4:1.0 and during the flotation lead is inclined to go with pirotines concentrate more than is allowed. We are strongly focused to maximally decrease the Pb amount that goes with pirotine concentrates and wastes. The paper as such gave the first effects in optimizing of these parameters with positive effects in flotation process in Trepca.

Mar 1, 2018

By Won C. Park

Experiments showed changes in the mineral content of dolomitic oil shale at temperatures and exposure times which bracket conditions encountered during in situ retorting. Laboratory results correlate with cores from a spent in situ retort at Occidental's Logan Wash test site at Garfield County, Colorado. Dolomite, CaMg(CO3)2, decomposes rapidly to form periclase, MgO, calcite, CaCO3, and CO . Both calcite and periclase are intermediate products that can be stabilized by CO atmosphere at lower temperatures, while steam accelerates the formation 2 of silicates. The decarbonation of calcite appears to involve a direct reaction with both quartz and periclase in forming these silicates. Decarbonation preceeds the formation of akermanite, Ca2 MgSi 207, and diopside, CaMgSi 206, within several hours of heating and is followed by the nucleation of forsterite Mg2SiO4, and monticellite, CaMgSiO4. Under in situ retorting conditions, akermanite and diposide are the major minerals above 800°C. Equilibrium is not attained within 200-300 hours. In situ retorting temperatures above 800°C for extended periods of time should reduce potential ground water leaching by the formation of silicate minerals. These silicates are less soluble than free lime, magnesium or alkali oxides. There is a corresponding decrease in the natural pH of these silicates from approximately 12 down to 7.5 to 9:

Jan 1, 1981

By A. Broussaud

An original methodology has been developed for steady state simulation of selective grinding and mineral liberation in rod and ball mills. Three fundamental aspects of the methodology are presented successively : modeling ore texture, modeling grinding and its selectivity, and modeling mineral liberation. The methodology for modeling ore texture includes the conversion of 2D data into 3D reconstructed information and the use of the BILCO coherent material balance software. The models for grinding Simulation are classified into three levels, corresponding to three levels of available experimental data. All models account for grinding selectivity and for variations of engineering para-meters and operating conditions. An algorithm has been introduced to forecast mineral liberation, compatible with accurate simulation of selective grinding, which generates reasonable results.

Jan 1, 1987