Search Documents

By Kurt Westerlund

Three. years operating experience of the FLUXFLOW waste heat boiler (WHB) 20.000 nm /h at Boliden Ronnskar Sweden on a TBRC smelting palena (PbS). Operating experience from the Kivset flash WHB 11.900 nm /h at Samim, Porto Vesme, Sardinia, Italy. Conceptual features of the 93.600 nm3 /h FLUXFLOW (WHB) on the Isasmelt smelting in melt furnace for 180.000 t Cu/a at Mount Isa, Australia.

Jan 1, 1992

By Corale L. Brierley

Bioheap leaching, commercially applied for secondary copper ores and agglomerates, is rapidly gaining popularity. Bioleaching of chalcopyrite concentrates is imminent. Copper bioheap leaching encompasses the bioleaching of acidified and agglomerated coarse, secondary copper ore, stacked on permanent or on/off pads. The stacked ore is irrigated with raffinate containing bacteria. LME-grade cathode copper is produced by SX/EW. Low capital and operating costs, rapid start-up, environmental benefits, operational simplicity and a good performance record make bioheap leaching an attractive technology. This paper looks at the state-of-the-art of copper bioheap leaching and chalcopyrite concentrate leaching, the risks, the benefits, costs, bioheap performance and the future prospects of copper bioleaching.

Jan 1, 1999

By O. Kitamura, H. Kubota

The Harima Works started its ISP operation in 1966 and been expanding its production capacity from 3,000 tonne Zn/month and 1,500 tonne Pb/month to 7,500 tonne Zn/month and 2,500 tonne Pb/month. It is not only treating zinc, lead and bulk concentrates but also secondary materials like Waelz kiln oxide from the Shisaka Works of Sumitomo Metal Mining, waste treatment sludges, industrial wastes and others. Its final products cover Prime Western Grade (PWG) zinc, Special High Grade (SHG) zinc, continuous galvanizing grade zinc, electrolytic lead, cadmium, indium, thallium and sulfuric acid. This paper briefly describes the smelter's historical and present operations. The key data for the current impurity control management and for the distribution of impurities such as copper, iron and arsenic are presented.

Jan 1, 2000

By Jean-François Domgin

This paper aims at presenting numerical results showing the impact of different parameters on the limitation of entrained slag from ladle to tundish during the ladle drainage. These parameters are process parameters, slag properties or external actuator acting directly on ladle slag behaviour. Numerical simulations based on the use of the CFD Fluent software illustrate the vortexing and non-vortexing phenomena appearing during the ladle drainage. This numerical tool validated by experimental data acquired on water model has been applied to industrial configurations. It shows that the slag properties (viscosity, surface tension?) or some modifications of parameters (slide gate opening, geometry of the ladle bottom?) have a positive effect on the slag entrainment and also on the decrease of the ladle heel. Finally, the modelling of the behaviour of an external actuator injecting some gas in the region of the nozzle reveals interesting possibility for reducing slag entrainment from ladle to tundish during the final steps of the drainage.

Jan 1, 2006

By Y. Sako, E. Nomura, K. Muraguchi, K. Shibata

In 1998, Mitsui Mining & Smelting Co., Ltd. (MMS) produced 70,000 tonnes of lead, 231,000 tonnes of zinc and 214,000 tonnes of copper. MESCO, Inc. has been in charge of the automation and mechanization of smelting facilities promoted by MMS as well as the construction of facilities for chemical production and electronics materials plants, by which MESCO has contributed to the development of MMS. Initially, MESCO developed a casting machine for refined lead in the early 1960's, and thereafter, it developed a casting machine for refined zinc, a stripping machine for zinc tankhouses and energy saving facilities. In the field of copper smelting, it has also developed automation and mechanization facilities.

Jan 1, 2000

By H. Roberts, C. Hassall

The opening years of the new millennium will be characterised by the closure of many lead and zinc mines because of reserve depletion. However, weak commodity prices through the second half of the 1990s have slowed project evaluation and have made it difficult to raise finances for the development of new mines required to replace lost output and to meet increasing demand for metal in the future. Growth of lead and zinc demand will be determined by the pace of global economic activity, especially in the emerging economies. How rapidly demand grows will have a key bearing on the possible shortfall in mine output and the response of prices to the implied tightening of metal supplies early in the new millennium. These issues are the focus of a discussion of the critical lead and zinc supply developments which will unfold post 2000, taking into account project lead times and the role that recycled metal plays in meeting market demand.

Jan 1, 2000

By M. A. Llavona

The study of the formation and components of copper patina and its conservation has assumed great importance. The changing environment has accelerated the processes of patinas degradation; thus, the exhaustive study of factors capable of affecting the patina formation, growth and durability has assumed great importance for the industrial activity of copper. The main components of the patina, oxides, chlorides, nitrates and sulfates, have been determined; the effect of physical, chemical and microbiological factors on patina formation, particularly the influence of acid rain, natural organic matter, particles and microorganisms have been defined. The effect of different electrolytic solutions that accelerate the formation of copper patinas has been determined, and a review of the state of knowledge of the formation and evolution of metal patinas has been made.

Jan 1, 1999

By Romeo U. Pagador

After privatization in 1999, PASAR Corporation initiated a plant modernization program to optimize the performance of the smelter by increasing plant availability. This initiative required operational adjustments to the converting and anode furnace procedures, to support the higher throughput in the flash furnace, while continuing to meet government environmental regulations. The major shift in production direction was to eliminate the 30-35 day maintenance shutdown every two years, and replace it with a 15-day shutdown. This paper discusses the changes implemented in the converter and anode operation that have resulted in an increase of 10% in flash furnace throughput, an 18% increase in blister output, to 170 tonnes per cycle, and a converter campaign tonnage increase of 10%. Since privatization, PASAR has instituted a series of ?management of change? programs that have facilitated an industrial cultural change needed to achieve the company?s vision, mission and strategic goals.

Jan 1, 2005

By Marcelo E. Andia

In Chile, a significant amount of mining takes place in varied geographical environments. Mining activity extends from copper and gold deposits located in the Atacama Desert 4.500 meters above sea level to underground coal workings beneath the sea floor. This diversity in location and environment presents many challenges in the development of competitive and environmentally sustainable mining activities. An important future issue will be how to close these mines in an appropriate way once economically exploitable ore reserves have been exhausted. This poses challenges for both the government and companies alike, considering that Chilean law currently lacks legislation specific to mine closure. This paper examines the risks associated with mine closure based on international experience, and identifies those risks specific to Chilean regions. The main regions in Chile where mine closure legislation should be applied are identified.

Jan 1, 1999

By Jason Eric Sallee

Ongoing operations at the Cyprus Miami Smelter involve the use of an electric furnace for settling of copper matte from discard slag. Proper operation of the electric settling furnace is a major factor in minimizing losses of copper to the discard slag. Recent test work at the smelter has shown improvement in the operation of the electric furnace with a subsequent improvement with regard to the copper losses. This paper presents a general discussion of the Cyprus Miami Smelter operation, past results with respect to copper losses, recent operational changes and test work, and the subsequent results.

Jan 1, 1999

By M. Boussuge, M. -D. Dupuits, A. Piant

This paper summarises a part of the work that has been essentially carried out at the Ecole des Mines de Paris in the framework of an Eureka European programme funded by the French Ministry of Industry, in partnership with Metaleurop and Carborundum (subsidiary of Saint Gobain). It deals with the measurement of different properties (density, thermal linear expansion, elastic modulus, strength) of a SiC-based refractory constituting the trays that are used in the refining columns in the New Jersey zinc distillation process, especially in the boiling section. These parameters have been investigated to check the homogeneity of the asreceived trays as well as to estimate the influence of ageing of the material under operating conditions. With this aim, specimens have been sampled in used trays having more than two years of operation. The as-received trays exhibited a good homogeneity, the strength being slightly lower in the direction in which they are compacted. Despite microstructural changes, most of the properties measured at room temperature are not significantly affected by ageing. High temperature tests involved thermal treated under vacuum to remove metallic zinc before testing at high temperature. An increase in temperature, as well as ageing, induces a decrease in the elastic modulus and strength.

Jan 1, 2000

By S. Motoiu

Data acquisition is widely used for controlling flash smelting furnaces. A Romanian smelter from which a large amount of data can be collected uses such a technique. A computer program was developed for interpretation of the data. Inputs to the program are the process data files. Abnormal data are identified using standard statistical techniques; they can be edited if necessary. The following methods can be used for the analysis: linear correlation (single or multiple), polynomial correlation or comparison of two average values. Time variation graphs and histograms can be displayed. The random balance method was used for determination of significant parameters influencing the process performance. Not all process parameters are recorded, and some of them are not even measured. The software can compute some of these parameters such as: air flow rate required and the oxygen content of the gas: exiting the reaction tower. The software was used for the interpretation of a large amount of process data. The analysis showed that the process did not operate properly at some times.

Jan 1, 1999

By I. M. Santos Moraes

Achieving high current efficiencies when operating at high current densities is a goal for every refinery, whether conventional or permanent cathode technology is employed. To obtain higher current efficiency at increased current density at Caraiba's Tankhouse, the production team decided to change the cathode cycle from eleven to thirteen days, reducing cathode cycle to one per anode cycle. The idea was to reduce the anode-cathode spacing and consequently reduce the potential for short-circuiting them. With respect to current efficiency, the overall result was not much better than that obtained with the normal operating conditions. A new attempt to obtain higher current efficiency at high current density was implemented by going back to two cathode cycles per anode cycle, this time reducing cathode life to ten days. This approach yielded the highest current efficiencies. This paper presents the data generated with the three operating conditions: normal practice, a single cathode cycle per anode cycle, and two cathode cycles per anode cycle with a reduced cathode cycle time. It compares the productivity achieved with each set of operating conditions. An analysis of the main operating parameters as well as the advantages and disadvantages involved with each condition is also presented for future reference.

Jan 1, 1999

By Thomas K. Chow

For the well-being of all living creatures and in response to green-environment policy from governments around the global, it is essential to reduce SO2 emissions from mining / smelters as well as other industrial facilities around the globe. However, often times, these SO2 containing flue gases and smelter flash gases also include oxygen and SO3, which complicate the SO2 removal process and technology. There are many novel technologies recently developed for removing SO2 from such gases. Most of these, however, have not yet commercially demonstrated that they are technically viable and economically feasible. Many of these novel processes also generate undesired byproducts, which themselves then need to be disposed of in a safe and cost effective manner. Fluor has developed the Fluor SOx Cleanup Process with a wide variety of process configurations to customize removal of the undesired flue gas constituents in a cost-effective manner. The process removes practically all SO2 in the form of salable elemental sulfur and also reduces CO emissions. Successful operation of major components of the Fluor SOx removal technologies has been demonstrated in many commercially operating units. Besides their technical viability and economic feasibility, Fluor SOx removal technologies do not generate any undesired byproducts or encounter SO2 associated corrosion issues. Moreover, these technologies produce high-purity, saleable elemental sulfur. This paper discusses the merits of the Fluor SOx removal technologies, their technical and cost advantages, their simplicity in design and operation, and their readiness for implementation.

Jan 1, 2006

By Anthony C. Mulligan

Metals have historically been used in mining since they offer an excellent combination of hardness, toughness and cost and can be fabricated to form a variety of shapes. However, for many applications the metals used today have limited performance in the environments in which they are needed. This is particularly true for geothermal environments where the brines are highly siliceous causing corrosion and accelerated wear of many components. Geothermal sources are increasingly being explored for their high thermal value as well as possible sources for future minerals. While advanced ceramics have historically been expensive to produce in comparison with metals, they offer significantly greater corrosion resistance and hardness and can improve the overall performance when used in selected ?problem? areas. One of the major drawbacks in the use of ceramics in high impact areas has been their brittle nature and propensity to fracture and spall (fail) when loaded. Recent advances in the fabrication of ceramics have combined hard (strong) ceramics with more ductile ceramics in a architecturally designed microstructure, thus allowing ceramics to perform well in these high impact regions. Additionally, ceramics are significantly more inert to corrosion from either alkaline or acidic environments and can typically be used for significantly longer periods in these environments than their metallic counterparts.

Jan 1, 2006

By M. M. Salari Rad

An investigation of gold distribution in the mill products of Sar Cheshmeh beneficiation plant demonstrates that on average 44% of the gold is routinely recovered as a by-product in the copper concentrate, and the remaining is lost to the tailing. In order to evaluate the causes of gold losses, the distribution and mode of gold occurrence in the Sar Cheshmeh ore and mill products were studied. Searching for gold within samples and within individual grains of sulphide minerals was carried out by SEM in the backscattered electron mode and SIMS, respectively. The mineralogical distribution of gold revealed by microbeam techniques were combined with the results of relevant metallurgical experiments including, sizing, heavy liquid separation, and diagnostic leaching tests, and the nature and location of gold in the ore and mill products were determined. The combined results of the experimental approaches pursued suggest that while there are some gold in solid solution and/or -colloidal size within sulphides of the Sar Cheshmeh ores, "visible" gold is the principal form of gold occurrence at Sar Cheshmeh.

Jan 1, 1999

By Roberto Parra, Roberto Parada

"A novel process for minor elements control in copper pyrometallurgical production is proposed based on a theoretical analysis and the results of an experimental program. Its application can solves operational problems related to volatile elements that determine pollutants gas emissions and the final quality of anodes. The process considers a calcination of mixtures of the dust with sulfidizing agents such as dirty copper concentrate or elemental sulfur at temperature under 800 °C. The product are a clean calcine that recovers all the Cu content on the dust and a gas stream that collect the minor elements as sulfides species. The calcine can be returned to the smelter avoiding the As increasing in the circuit and so on, the capacity for the treatment of dirty concentrates for the smelter can be higher. The possibility to apply vacuum in the calcinations step can decrease the operation temperature. The solid condensed from the gas has different options for its stabilization, with the advantage that this stream represents few mass with high As content.IntroductionThe control of undesired minor elements (IVIES) in conventional pyrometallurgical copper production is especially relevant for ore deposits associated to Andes region. The concentrates that are being produced present every time higher levels of volatiles and harmful elements: group Va (As, Sb and Bi), Pb, Zn, and Sn."

Jan 1, 2008

By Leandro Voisin

A new pyrometallurgical treatment alternative is proposed for cleaning complex copper matte with high content of impurities in the copper smelting process, thus, in a suitable furnace, a given amount of pig iron will be added to the liquid complex matte with a matte grade between 65 and 75 % Cu under reducing condition and will produce three liquid phases of matte, copper-rich alloy and iron-rich alloy. Hence, in this study, firstly, a mass balance calculation was made on the basis of the reported data for the distribution ratios of the components among the three phases to define the optimum condition where most of the arsenic can be fixed in the less valuable liquid iron-rich alloy. By taking advantage of the high concentration of arsenic in the iron-rich alloy, the small volume alloy may be disposed in a yard, while the precious elements may be recovered effectively in the liquid copper-rich alloy and/or in the liquid matte. Secondly, laboratory-scale experiments were conducted to apply the proposed process to the matte produced from the slag-cleaning electrical furnace and the Teniente Converter of the Codelco-Norte smelter. The obtained results indicate that the proposed process for cleaning complex matte is promising.

Jan 1, 2006

By Jin-Chun Kim

Nanosized W based powders (W, WC, WC-Co) were produced by chemical vapor condensation (CVC) process. Two different solid W(CO)6 and Co2(CO)8 metal-organic materials were used as precursors. CVC experiment was conducted in the temperature range of 400-1100. As-CVC WC1-x powder which had non-stoichiometric composition was carburized by using of the CH4-H2 mixed gas in temperature range of 750-850. The CVC W and WC1-x powders showed loosely agglomeration structure, and the Co powder had intricate long stand structure because of intrinsic magnetic properties of Co phase. Carbon content of the CVC powders controlled by gas-phase carburization was well matched with theoretical WC stoichiometry (6.13wt%).

Jan 1, 2006

By Alex Moyano

The Codelco-Chile is considering different processing options for the projected concentrate from the Alejandro Hales mine (former Mansa Mina mine with high arsenic and antimony content of 6% and 0.6%, respectively), that will produce complex blister copper with high impurities contents, higher than the present values produced at the converting process of the Codelco Norte smelter processing only Chuquicamata concentrates. In order to know both the anodic copper quality and the metallurgical implications when a complex blister copper is processed in the refining process of the CN smelter, the Codelco and IM2 ?task force? evaluated positively the refining process for the complex blister copper by addition of alkaline fluxes at laboratory and industrial scale tests. The promising results of the tests done at laboratory scale at the Tohoku University facilities, allowed a large scale test planning to validate the lab-scale results in 3 refining furnaces of 250 t capacity at the CN smelter. The obtained results demonstrate the industrial technical feasibility to process a complex blister copper in the refining furnaces producing an anodic copper quality suitable for the electrolytic process.

Jan 1, 2006