To be Updated with new approved abstracts

ASARCO LLC (Asarco) and its parent Grupo México, S.A.B. de C.V (Grupo Mexico) are of the view that a renewable energy project can be viable use of un-utilized mine lands and post-mining use of disturbed mined lands that have been reclaimed. This paper examines the drivers that make mining and solar energy development a good fit and, through a case study, discusses Asarco’s experience in hosting the Avalon Solar Project, a 57-megawatt (MW) single-axis tracking solar power photovoltaic (PV) facility situated on approximately 500-acres tract of retired agricultural land, acquired for water rights purposes, in Pima County, Arizona near the Asarco’s Mission Complex. The paper also discusses the reclamation of the San Xavier tailings storage facilities and waste rock deposition area, located within the boundaries of the San Xavier District (District) of the Tohono O’odham Nation where a portion of the Asarco Mission mining operations occur. These and other closed and reclaimed tailings storage facilities and possibly waste rock deposition areas could be suitable for siting future photovoltaic (PV) solar projects.

Silica-sol bonded no cement castables have been used in the refractory industry in the last years due to some important advantages such as fast dry-out, lower open porosity, very high thermal shock resistance and excellent mechanical properties at high temperature. Binder selection plays a very important role in the phase evolution, final microstructure and ending results on the field. Some of these are absolutely important skills on metal or slag contact areas, where diffusion and corrosion phenomena are one of the main wear causes.
This paper is focused on main goals to be achieved, adapting the castable formulas to special requirements in some areas of Copper, Lead and Aluminum industrial processes.
Cold Crushing Strength, Hot Modulus of Rupture, Young's Modulus, Dry-out obtained by Macro Thermo-Gravimetrical Test developed by ALFRAN, Corrosion test by Aluminum alloy following several standards, are some of the properties analyzed on developed materials. Furthermore, some case studies were shown, comparing the traditional LCC castables with sol-gel NCC castables performance on the field.

Since 2009, Cobre las Cruces (CLC) is operating successfully an integrated mine and hydrometallurgical plant near Seville, Spain. The CLC hydro plant deals with chalcocite ores through direct atmospheric leaching process followed by solvent extraction and electrowinning. CLC is producing about 72,000 t/y Cu cathode, Grade A, 99.999% Cu.
Throughout these years, continuous improvement has been one of the main bases of CLC strategy, trying to increase the efficiency of the production process.
The last steps have been to improve the copper losses. A set of press filters were installed to minimize copper losses increasing washing efficiency and produce a drier and cleaner residue. This issue allowed recovering around 1,500 additional ton of copper per year.
During commissioning and startup of the new filter availability issues were detected due to gypsum scaling. To minimize this effect two pulp coolers were installed resulting an increase of 10% in availability.
The new slurry cooling towers provides a more effective process configuration to CLC hydro plant, adding two additional advantages: (i) evaporated water has been substantially increased, improving the plant water balance; (ii) gypsum scaling has been reduced improving SX performance (less TSS in SX feed).

The Copper Smelting Industry has transitioned into the new millennium compliant with environmental regulations, new smelter installations, and brown field expansions.
The industry faces new challenges to achieve economies of scale for maximizing copper throughput as copper in concentrate grades have decreased while contained impurities have increased.
This paper compares Double Flash, TSL, Mitsubishi, and Bottom Blown smelting technology flexibility to process current grades of concentrate in the custom market.

The oxygen bottom blown copper smelting process is a new technology which has been widely applied to the copper production in China. In this work, a computational thermodynamics model for this technology has been established, based on smelting mechanism and theory of Gibbs free energy minimization. The calculated results from the model agree well with the actual industrial data, indicating that the model can be used for the predictions under different operating conditions. The tendencies of the key parameters (such as Cu losses and Fe3O4 content in slag) and the distribution ratios of the minor elements (such as Pb, Zn, As, Sb and Bi) can be predicted by adjusting the oxygen/ore ratio charged into the bottom blown copper smelting furnace. The model can be used to monitor and optimize the industrial operations of the oxygen bottom blown copper smelting process.

System MgO-SiO2-Al2O3 has a great practical importance, and its phase diagram can used for the description of properties of advanced and building materials as well as for the characterization of geological objects too. Data for invariant processes in the binary and ternary systems (with taking into account the existence and type of binary and ternary compounds) is the base for creation of schema of mono- and invariant equilibria.
The system MgO-SiO2-Al2O3 includes four binary compounds and two ternary compounds. It�s characterized by 11 invariant transformations: three eutectics, one peritectic, five quasiperitectic equilibria and two four-phase regroupings of phases with polymorphous modifications of silicon oxide (cristobalite and tridymite). Obtained computer model of phase diagram for system MgO-SiO2-Al2O3 includes liquid immiscibility surface, 10 liquidus surfaces, 78 ruled surfaces, 11 horizontal complexes at the temperatures of invariant points, 21 two-phase regions and 29 three-phase regions.
Such full model of phase diagram including all topological elements makes possible to calculate the horizontal and vertical sections and the crystallization paths in any part of phase diagram. The crystallization paths are confirmed by the diagrams of vertical mass balance, which permit to obtain the lists of intersected phase regions and the crystallization stages for given mass center over the entire temperature range. As a result we can identify the list of microconstituents for each concentration field the base of this investigation.
Key words: phase diagram, computer model, crystallization paths, system MgO-SiO2-Al2O3.
This work was been performed under the program of fundamental research SB RAS (project 0336-2016-0006), it was partially supported by the RFBR (projects 15-43-04304, 17-08-00875) and the RSF (project 17-19-01171).

The industrial manufacturing of ferronickel in electric furnaces produces large amounts of slag with strong acidic character and high melting points, which seriously stresses the furnace refractory. In this study, measurements by a hot stage microscope served for the determination of melting behaviour of synthetically produced ferronickel slags on magnesia as refractory material. Therefore, 13 different slags comprising the main oxides SiO2 (35 to 70 wt.-%), MgO (15 to 45 wt.-%), Fe2O3 (5 to 35 wt.-%) and Al2O3 (0 to 10 wt.-%) were melted in a graphite crucible and afterwards analysed by a hot stage microscope. The design of experiments, which was created by the statistic software MODDE, included 15 experiments with varying slag compositions as well as atmospheres. The evaluation of the test results occurred at three different characteristic states of the samples like the deformation point according to DIN 51730 and the temperatures, at which the area of residual cross section of the samples amounted to 30 respectively 40 % of the original value in dependence of their SiO2/MgO ratio and iron oxide content. Additionally, the thickness of the zone influenced by the slag was measured and evaluated. The results indicated that the deformation temperature decrease with an increasing content of Al2O3 and SiO2/MgO ratio. Furthermore, a content of 4 respectively 10 wt.-% Al2O3 resulted to the lowest temperature for 40 % residual cross section. In addition, the alumina content showed a changeable influence on the area of influenced zone of the refractory at high and low SiO2/MgO ratios.

In flash smelting and converting, burner performance depends on achieving a uniform spatial distribution of feed, and an optimal distribution of particles of different size in the feed plume. Matte and concentrate burners typically achieve this by using feed distribution air, which is introduced radially through nozzles located at the burner lance tip. Conventional distribution air nozzles comprise several cylindrical holes drilled in the outer circumference of the central jet distributor. Conventional nozzles, particularly those in flash converters and direct-to-blister furnaces, are prone to clogging by built-up accretions. This can degrade burner combustion performance over time, by introducing asymmetries to the plume and particle distribution. Due to excess clogging, these nozzles may need to be frequently cleaned, which leads to frequent furnace downtime. Recently, Hatch and Rio Tinto Kennecott Copper (RTKC) have conducted trials of new proprietary distribution air nozzle designs. Two of the nozzle designs have shown a three-fold improvement in cleaning related downtime, and a 2–3.5% reduction in oxygen requirements per ton of smelted matte. Initial observations also indicate easier to remove reaction shaft accretions using one of the nozzles. A third distribution air nozzle is scheduled to undergo testing soon, at the time of writing. The new nozzle designs represent an inexpensive, low-risk means for improving the combustion performance and maintenance requirements of flash furnaces, leading to substantial economic performance improvements.

There are two hundred varieties of minerals containing rare earth elements (REEs). Among all, only three minerals namely bastnaesite, monazite and xenotime are having the significant amount of the REEs. Monazite, being the second abundant source of rare earth, contains radioactivity elements such as thorium. In hydrometallurgical process for recovery of REEs from monazite ores, thorium is discharged as radioactivity residue/slag which does not only harm to environment and human beings. Therefore, thorium has been considered as unwelcome material incorporated in monazite. However, the demand of thorium is increasing day-by-day due to its diversity of industrial applications. Especially, interest in the commercialization of a thorium fuel cycle for generating nuclear power has been lately much increased.
Hydrometallurgy is the most important field in metal recovery technology. For thorium recovery from monazite, solvent extraction is the key technique and most reliable method to reach target metal recovery with as much as minimum waste generation. In this work, the separation and recovery of thorium from monazite ore leach liquors by use of solvent extraction method were studied. Five different types of extractant were tested and the better extractant systems were identified. Further, separation of REEs from thorium, scrubbing of the co-extracted elements was studied. Finally, the recovery studies were established.
More details will be discussed in the presentation

Process vessels such as smelting furnaces and acid towers are lined by refractory bricks. Degradation of the refractory lining in smelting furnaces begins since the start of the operation. For acid towers, the failure of castable refractory or the mortar between the refractories can cause high concentration acid leaks. Eventually the lining degradation becomes crucial and requires replacement. Since shutdowns are prohibitively expensive, it is desirable to identify the damaged areas and schedule maintenance shutdowns at the optimal frequency so as to reduce the cost of repair and shutdown periods. For this reason, non-destructive testing (NDT) techniques are developed to determine the lining condition while the vessels are still on-line. In this paper, we discuss the application of discrete Acousto Ultrasonic-Echo (AU-E) measurements and real-time continuous Acoustic Emission (AE) monitoring for the determination of refractory lining integrity in smelting furnaces and acid towers.

This paper is an update of a keynote talk with the same title at the 2011 Fray Symposium in Cancun, Mexico in 2011, at which ASARCO LLC received the Fray International sustainability award for its on-going sustainable development initiatives. It attempts to answer the often-asked question of whether metal mining (defined broadly to incorporate mining, beneficiation, smelting and refining) is compatible with the concept of sustainable development. Starting with the classic Brundtland Commission definition of sustainable development as development that meets the needs of the present without compromising the ability of future generations to meet their own needs, it makes the case that mining can and should be sustainable, using select examples of sustainable mining practices at Asarco. These examples cover the entire mining cycle starting with exploration, operation, closure and post-closure and post mining land use.

Huge amounts of low-quality secondary zinc oxides are produced by the recycling of steel mill dust or other zinc-containing residues. Due to different impurities the utilization of secondary zinc concentrates, such as waelz oxide, is currently limited to primary zinc industry, undergoing the whole process chain from roasting to winning electrolysis or alternatively solvent extraction and electrolysis.
The paper discusses the background of the necessity of purification steps like roasting or solvent extraction as well as the disadvantages of these procedures.
Furthermore, opportunities of how to bypass such steps and by doing this, give more value to the secondary zinc oxides, are described. In this special field, Montanuniversitaet Leoben was able to develop some important procedures whereof one is currently patented. Focus on the investigations was especially on the Zinc-Iron separation and the removal of fluorine-containing compounds.
Results of various trials improving the zinc oxide quality are summarized and a discussion of economic aspects is performed within the paper. Also included is an evaluation of the world wide potential and an outlook of possible implementations of developed concepts.

The effect of red mud on the melting behavior of ferronickel slag was investigated in a laboratory-scale horizontal tube furnace. Melting and softening of slag samples fluxed with different amounts of red mud were examined by an in-situ visualization technique in the temperature ranges from 1673 K to 1823 K. FactSage�a 7.0 was used to perform thermodynamic calculations of the multi-component system of ferronickel slag and red mud. The liquid phase area was extended to lower temperatures by adding red mud, and this implied that red mud was an excellent flux. The primary solid phase field was confirmed to be dependent on the red mud content from X-ray diffraction measurements. Microscopic observations using a scanning electron microscope (SEM-EDX) confirmed that the primary solid phase changed from olivine to spinel with the addition of red mud.

FLOGEN CONTOP offline and online control expert system was commissioned in Paranapanema smelter in Dias D'Avila to compare different scenarios and support for the optimization of the Hoboken Converters operation. The software results indicate the possibility to decrease the amount of silica used as a flux, minimize the slag and copper blowing time, maximize the use of reverts, minimize slag volume, and decrease copper losses in the slag. The main process parameters (such as bath temperature, Sulphur content in Blister and Copper in the slag) is calculated during the operation, providing a clearer overview of the process and supporting to determine the end of blowing based on technical evaluation. This presentation will describe some of these achievements.

Due to the rich sources reserves of raw materials depletion and the increase in demand for rare and rare-earth metals in such fields of technology as electronics, electrical engineering, metallurgy, and nuclear power, in recent decades the attention of researchers has been attracted to the problem of processing non-traditional rare metal, in particular eudyalite raw materials. Earlier studies of pyrometallurgical processing of eudialyte concentrates containing up to 55% SiO2 and 9 - 17% ZrO2, have shown promising results in the use of aluminothermic reduction. At the same time, it was revealed that the metallothermal process is complex and requires further study. The purpose of this work was to identify the sequence of intermetallic compounds formation during interactions at the Al-ZrO2-SiO2 system. The use of thermodynamic calculations, methods of differential thermal and X - ray phase analysis made it possible to simulate the interaction process in the Al - ZrO2 - SiO2 system and to establish that the prevailing formation of zirconium aluminides will take place at the initial stage at temperatures above 900°C at the aluminothermic co-reduction of zirconium and silicon.

Pirdop copper smelter and refinery is the biggest facility for smelting and refining of copper in South-Eastern Europe. The plant was commissioned in 1958 and had an initial annual capacity of 160,000 tons of anode copper. Today the plant has reached a capacity of 350,000 tons of anode coper, 230 000 tons of cathode copper and 1,220, 000 tons of sulfuric acid. Besides copper it produces also other quantities of silver, gold and selenium.
This presentation will first give an overview of the overall growth history of the copper production of Pirdop copper smelter and refinery since its commissioning in 1958 followed by an analysis of the progress achieved in the last 10 to 15 years. Major investments during this period are described along with their significant results in achieving the company sustainable development in terms of the modernization of the process and production, protecting the environment and developing the society.

In the actual global chain of high-tech products, such as smartphones or communication satellites, specific wavelength lasers, catalyzers, etc., rare earth elements (REE) are important raw materials. In 2015, the global estimated production was 124 kt, and China alone produced 105 kt. Although the production and demand for REE are well established, there is a worldwide effort to find new resources and technologies due to the high demand foreseen for these elements in the near future. Acid Mine Drainage (AMD) can be a secondary resource of REE, since it is a natural and continuous leaching process of rocks or waste piles. For example, in The Osamu Utsumi mine (Minas Gerais-Brazil) the AMD waters contain around 130 mg L-1 of total REE - the light ones being the majority. Considering a flow rate of 150 to 300 m3 h-1, it is expected to recover up to 468 to 936 kg of REE per day, what is quite considerable. In AMD waters, iron and manganese (hydr)oxides are ubiquitous minerals and their importance on the retention and transportation of U, REE and other metals is well known. Previous studies showed that some REE can be immobilized by iron (hydr)oxides in acid solutions, with posterior selective extraction. This study aims at concentrating the REE present in AMD waters by co-precipitating it with synthetic Fe, Al and Mn (hydr)oxides. AMD was simulated using a laboratory solution with pH = 2.6, sulfate content of 2 g L-1 and total REE content of ~130 mg L-1. Different amounts of FeCl3, Al2(SO4)3 and MnSO4 0.5 mol L-1 were added to the laboratory solution in order to reach distinct Fe:Al:Mn:REE molar ratios. The pH was adjusted to 6±0.3 using KOH 2 mol L-1. Results showed that for some experimental conditions, the effectiveness of the removal of REE were above than 90 %. It was obtained an amorphous solid phase with ~17% of REE oxides using a molar ratio of 16:0:4:1, with 98% of removal effectiveness. Further studies will focus on the increase of REE content in the solid phase, followed by the leaching of these elements with acid and saline solutions, aiming to obtain a REE concentrate.

The recovery of rare earth elements (REEs) from acid mine drainage by cationic resins was investigated using batch experiments. The experiments were carried out with laboratory solution and with acid mine water enriched with REEs. The experimental conditions were: pH 1.3, 2.5 and 3.4, temperature 25±1⁰C, and the exchange resins were Dowex 50WX8 and Purolite C160. For the laboratory solution, it was observed that for all the REE, except cerium, the adsorption was > 85%. For the spiked acid water, the best results were obtained at pH 1.3 and the adsorption capacity of the resins for the REEs in mmol.g-1 are: Dowex 50WX8 (La=0.074, Y=0.067, Ce=0.079, Pr=0.077, Nd=0.077, Eu=0.070, Dy=0.070, Sm=0.074); Purolite C160 (La=0.074, Y=0.059, Ce=0.080, Pr=0.077, Nd=0.076, Eu=0.070, Dy=0.066, Sm=0.074). The highest adsorption was obtained for La, around 89% for both resins. The resins also adsorbed other elements from the spiked acid water, such as Mn, Ca, Mg, Zn and Al. The resins adsorbed less than 10 to 12% of these elements, considered as impurities. The total loading capacity of the resins is 0.668 mmol g-1 for Dowex 50WX8 and 0.643 mmol g-1 for Purolite C160. However, the results showed that the resins have similar adsorption capacity for the REE.

A recycling of waste solar modules has been increased attention with development of the photovoltaic market in the world. In this study, two kinds of acid treatments were carried out to examine the optimal recovery condition of silicon and the other metal elements in waste crystalline silicon solar cells. Mixed solution of hydrofluoric acid (HF) and nitric acid (HNO3) was used to maximize the remainder of etched silicon wafer, whereas that of hydrochloric acid (HCl) and HNO3 to remove metallic elements such as silver (Ag), copper (Cu), tin (Sn), aluminum (Al) from crushed and granular mass of waste crystalline cells and obtain the maximum purified silicon particles. The effect of HF/HNO3 concentration on etching rates of several components such as Ag, Al, anti-reflection film made of silicon nitride (AR) and Si in the solar cells was made clear that Al, AR and Si etching rates peaked at the HF mole fraction of about 0.8 and depended on HF more deeply than HNO3.On the other hand, when the mixed solution of HCl and HNO3, Cu etching rate was less than the other elements such as Ag, Al, Sn etc.

Under an umbrella of the risk of climate change, the copper extraction process is seeking for the innovation in order to attain the saving energy and workload using IoT and so on. Many metallurgists are devoting their R&D activities to higher productivity and continuous smelting processes. More directly, it faces many troublesome issues such as scarcity of natural resources with lower Cu grade and higher impurity contents in its concentrates. The world needs more copper for the society amenities, then recycling from the wastes and recovery of copper from tailing dams in which some 10 - 15% of excavated copper sleeps should be accomplished. Lower Cu grade in concentrate urges the process and the industry to extract excess reaction heat in smelting furnaces, to treat bigger amount of smelting slag where the valued metals should be retrieved if possible, and to market excess sulphur by-products. Elimination and stable fixation of toxic impurities such as Hg and As are urgent concerns for metallurgists.
In the paper, some ideas and research works done by the author such as copper ore leaching, elimination of arsenic from copper concentrates, recovery of molybdenum in a slag, new usage of slag, and production of elemental sulphur from smelting gas would be presented.

The smelting temperature is an important factor in copper smelting process by oxygen bottom blowing which affects matte grade, smelting slag type, properties of melt and furnace body erosion. It is the key that keeps the smelting process running normally. The production data is collected to calculate heat balance of copper smelting. Utilizing Fluent numerical software and coupling an equivalent solid heat source, the distribution of temperature is studied in the copper smelting process. Meanwhile, the effects of technical parameters, such as gas flow rate, the temperature of oxygen-enriched air, and bath depth on the distribution of temperature are discussed. The results showed that there exist a high-temperature zone in the action area of oxygen lance and the flue outlet. As gas flow rate increases, the smelting temperature decreases. The reason for this is that the smelting flue quantity increases and takes away more heat at a certain heat release rate. The low-temperature zone of oxygen lance opening expands as the temperature of oxygen-enriched air decreases which is in favor of protection of oxygen lance. The smelting temperature decreases as bath depth decreases, and the temperature is gradient distributed. This study simulated the distribution of oxygen bottom blown furnace, and has a certain guidance to the practical production.

Current practices for the processing of high-arsenic copper concentrates include: blending with large quantities of clean concentrate; roasting to produce a low-arsenic calcine; and direct smelting in a small number of custom smelters that accept arsenic-bearing concentrates. A sustainable processing alternative to process arsenic-bearing concentrates is via hydrometallurgy, including medium temperature leaching or total oxidative leaching at high temperature. The CESL Cu-As Process, a medium temperature and pressure hydrometallurgical leaching process, has achieved all operating and environment requirements in pilot and demonstration scale campaigns on several blends of high-arsenic concentrates containing up to 10% arsenic content. The benefits of the CESL Cu-As Process for processing of high-arsenic copper concentrates include >97% copper recovery to cathode coupled with >99% deportment of arsenic to stable residues with no particulate, sulphur dioxide, or liquid emissions. Short- and long-term stability tests on residue from the CESL Cu-As Process have proven the stability of arsenic in the crystalline ferric arsenates (basic ferric arsenate sulfate � �Type 2 Scorodite� � and scorodite) which presents an opportunity to sustainably and safely process high-arsenic enargite-bearing copper concentrates.

Rare Earth Elements (REE) are substances with physicochemical properties and characteristics of similar occurrence, 15 of them belonging to the series of Lanthanides, which together with Yttrium and Scandium total 17 elements. These, in turn, can be found in carbonates, oxides, silicates and phosphates and, particularly in Brazil, in Monazite and carbonatites. Due to the source material and the production methods used in the mines containing these minerals, it is expected that REE levels will be found in their products and by-products. In this scenario, the generation of tailings is inherent to any process of mineral processing and constitutes materials that do not present economic value, considering aspects of current market supply and demand. In this way, any initiative for its reduction or use can bring benefits, both from a financial and socio-environmental point of view, a challenge for sustainable development. China, the country with the largest REE reserve in the world, has been researching and using, since the 1970�s, fertilizers containing REE in their formulations for the development of plants. In Brazil, although a world-wide exponent of agriculture, there are no reports of such use on a commercial scale, except indirectly via phosphate fertilizers and soil acidity corrective, given that these inputs are capable of presenting REE contents as a function of the raw material source. In this context, the present research aims to carry out a systematic bibliographic review on the subject, seeking to understand the process of using the REE in the development of plants with a focus on the Brazilian potential for its use.

The gases from the Flash Smelting Furnace (FSF) and the Slag Cleaning Electric Furnace (SCEF) tapping operations are conducted through exhaust hoods located in the launders, to a baghouse filter in order to meet the current emission limits established in Atlantic Copper’s Environmental Permit (EP). This off-gas stream contains 20.9% O2 at environment temperature so that, once it has been dedusted, it can be partially recirculated as blast air in the FSF, with the rest being sent into the atmosphere. Foreseeing changes in European environmental legislation, and as a result of the latest revision of the best available techniques reference document on non-ferrous metals (NFM BREF) in compliance with the European Industrial Emissions Directive 2010/75 (IED), Atlantic Copper launched a project aimed at defining the most suitable SO2 abatement treatment of FSF and SCEF tapping ventilation system off-gas. Preliminary pilot tests were performed in SCEF tapping ventilation system in 2015 and 2016, which confirmed the expected SO2 removal using Sorbacal® SP and SPS. As a result of these promising results, a third campaign of tests was carried out in 2017 that confirmed the technical feasibility of the selected technology, based on SO2 dry abatement. This paper describes the results of these pilot-testing campaigns.

Two-step copper smelting process (hereinafter Fangyuan process) has been recently developed and patented by Dongying Fangyuan Nonferrous Metals Co., Ltd. and Shandong Fangyuan Nonferrous Metals S&T Co., Ltd ((hereinafter Fangyuan Company). This is the first and only process of this kind to directly produce anode copper by two steps in the world. This new technology to produce anode copper from concentrate includes two steps and can be summarized below. The raw materials, including concentrates and flux, are simply mixed without pretreatment and fed into Submerged Lance Smelting Furnace (SLS). High grade and hot white metal produced by SLS is sent to Submerged Lance Converting Refining Furnace (SLCR) via matte conduit. Two SLCRs work in turn to produce anode copper in order to maintain continuous operation of the whole production system. The new technology started its operation in October 2015 with the capacity to treat 1.75 Mt/a mixed minerals proved with various advantages. This paper will describe the industrialization application and development process of new technology at Fangyuan Company, with detailed discussion about its operation conditions and technical parameters.