Applications of Process Engineering Principles in Materials Processing, Energy and Environmental Technologies: An EPD Symposium in Honor of Professor Ramana G. Reddy: Pyrometallurgy I
Sponsored by: TMS Extraction and Processing Division, TMS Light Metals Division, TMS: Energy Committee, TMS: Hydrometallurgy and Electrometallurgy Committee
Program Organizers: Shijie Wang, Rio Tinto Kennecott Utah Copper; Michael Free, University of Utah; Shafiq Alam, University of Saskatchewan; Mingming Zhang, Arcelor Mittal; Patrick Taylor, Colorado School of Mines

Tuesday 2:00 PM
February 28, 2017
Room: 15B
Location: San Diego Convention Ctr

Session Chair: Patrick Taylor, Colorado School of Mines

2:00 PM  
Market Dynamics, Recycling and Recovery of Magnesium from Aluminum Alloy Scrap: Adam Gesing1; Subodh Das2; 1Gesing Consultants Inc.; 2Phinix,LLC
    This paper will provide an overview of North American and global current and future markets for magnesium and its alloy along with life cycle material flow diagrams. Additionally, we will provide a critical and global review of the current status and future developments in the production processes of magnesium and its alloys from various magnesium bearing raw materials including scrap. The main focus of the paper will be on collection, recycling and processing of post and pre-consumer magnesium scrap. We will discuss the latest status and economic analysis of RE12TM , a scrap-based process for recovering magnesium and its alloys for can sheet, automotive (body and closure sheets) and aluminum foundry applications.

2:20 PM  Cancelled
Alternative Ways of Using Nonferrous Slags as Feed Material in the Ferrous Production Industry: Mario Sanchez1; Fernando Parada2; Jose Palacios3; 1Universidad Andrés Bello; 2Universidad de Concepcion; 3Universidad de Playa Ancha
    As an alternative way of reduce the large amount of wastes generated during metallurgical processes in the primary copper production, the possibility of using the slag remaining iron as feed material for the iron and steel industry has been evaluated. Slags are generated during pyrometallurgical processing of copper concentrates in ratios ranging from 2 to 5 ton per ton of produced copper, and it contains 42 to 45% of iron. Thus, some laboratory research has been conducted, and, in an experimental run of slag oxidation followed by leaching and recovering of copper by SX-EW, the remaining solid was smelted and reduced with coke to produce a metallic phase containing 98% iron and 0.9% molybdenum. In further reducing steps, copper content is lower down and a molybdenum rich iron phase is obtained. Recovery of iron from copper slags considering reduction and control of detrimental elements for iron properties was studied.

2:40 PM  
Insulating or Conductive Lining Designs for Electric Furnace Smelting?: Joalet Steenkamp1; Glen Denton1; Derek Hayman1; 1MINTEK
    DC-arc furnace technology has been applied on industrial-scale in smelting processes since 1983. Applications include reduction of fine ores by carbonaceous reductants to produce ferrochrome and ferronickel alloys and high TiO2-slag, recycling of stainless steel dust and batteries to produce a chromium-nickel-rich and a manganese-rich ferroalloy respectively, and slag valorisation recovering a cobalt-rich alloy from slag produced in copper-smelting. Due to the high intensity of these furnaces, the power-to-feed ratio is an important process control parameter. Mismanagement of the power-to-feed ratio potentially has a negative impact on both the smelting process and the furnace containment system. Design of furnace containment systems can be based on two design philosophies: Insulating and conductive lining designs. The work presented here discusses the significance of the control of the power-to-feed ratio in the management of the furnace containment system, based on either design philosophy, within the context of ferrochrome production in South Africa.

3:00 PM  
The Influence of Phosphorous Additions on Phase Evolution in Molten Coal Slag: Hani Abu El Hawa1; Jinichiro Nakano2; Anna Nakano2; James Bennett1; 1National Energy Technology Laboratory; 2AECOM
    Carbon feed-stocks used in power, chemical, and metallurgical industries typically contain numerous minerals or impurities that liquefy during high temperature processing to form slag as a byproduct. Slags have many industrial applications, including as construction materials and for element recovery. In addition to other variables, the extent of slag utilization is dependent on its composition and post treatments. In this work, the influence of phosphorus additions on phase evolution in coal slag was investigated. Synthetic slag mixtures with varying AlPO4 contents were heated from 1380-1470°C in air, then water-quenched to preserve the phases formed. SEM/EDS, XRF and XRD analyses were performed before/after testing to gain insight about slag chemistry and phases present. It was found that coal slag exhibited a large solubility of phosphorous, affecting silicate phase stability formed under the conditions studied. Results obtained and their significance will be discussed.

3:20 PM  
Reaction Mechanisms in the Silicothermic Production of Magnesium: Mao Chen1; Yuhong Chen2; Fenglan Han2; Laner Wu2; Baojun Zhao1; 1The University of Queensland; 2Beifang University of Nationalities
    Magnesium is the lightest structural metal with a density only two-thirds of aluminium and one-quarter of steel. It can be produced by electrolysis of fused magnesium chloride or high temperature reduction of the oxide. The predominant method for magnesium production is the Pidgeon process which is a batch process starting from calcined dolomite and ferrosilicon. CaF2 is commonly used in the process as the catalyst. Analyses of the slag samples and thermodynamic calculations indicated that liquid phase plays important role in the reduction process. Effects of chemistry, temperature and gas pressure on the production have been discussed and compared with the operating data. Understanding of the reaction mechanisms will provide a fundamental base for alternative processes of the magnesium production.

3:40 PM Break

4:00 PM  
Influences of CaO/SiO2/MgO/Al2O3 on the Formation Behavior of FeO-bearing Primary-slags in Blast Furnace: Dongdong Wang1; Kaihui Ma1; Yang Xu1; Jian Xu1; Liangying Wen1; 1Chongqing University
    In this work, the softening and dripping experiments under the blast furnace conditions are designed to explore the influences of CaO-/SiO2-/MgO-/Al2O3 on the softening and melting properties of FeO respectively. The results indicate that additions of CaO or Al2O3 decrease the starting softening temperature and no dripping behaviors are found in comparison with the base case results when only FeO is used. On the contrary, the addition of SiO2 or MgO rises the starting and ending softening temperature, at the same time, both the dripping temperature and the maximum pressure drop of the case with the addition of SiO2 are the lowest among all the cases. According to the phase diagram and XRD analysis results, the initial phase with CaO addition in the primary-slags should be C2F (2CaO·Fe2O3) and that with SiO2, MgO, Al2O3 additions are fayalite (2FeO·SiO2), magnesioferrite(MgO·FeO), hercynite (FeO·2Al2O3), respectively.

4:20 PM  
Desulfurization of High Sulfur Coal Leached with H2O2 and NaOH by Microwave Irradiation: Pengqi Zhang1; Shengfu Zhang1; Lixiong Shao1; Mingcheng Bing1; Shuxing Qiu1; Qingyun Zhang1; 1Chongqing University
    Coal desulfurization has been regarded as an effective pretreatment for clean fuel and less environmental pollution. The microwave irradiation was used to desulfurize the Nantong coal leached with H2O2 and NaOH. The results showed the desulfurization rate of the coal is very low by directly microwave irradiation, while the coal samples leached with H2O2 and NaOH by microwave irradiation could effectively improve the desulfurization rate. The optimum desulfurization conditions were obtained as 10-mins irradiation time, 800 W irradiation power, particle size below 74 μm, 1:1 concentration ratio of H2O2: NaOH, in which the desulfurization rate reached 51.14% of the total sulfur content. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectra of coals structure before and after treatment have shown the bands in both coals changed slightly except the relative intensity of some absorption ones. It can be found that most of FeS2 and -S-S- functional groups transferred after treatment, while -SH and -S=O- had almost no changing by ATR-FTIR spectra analysis. The structures of coal matrix would not be broken by microwave irradiation in reasonable the reaction conditions.

4:40 PM  
The Recovery of Copper from Smelting Slag by Flotation Process: Jiaqi Fan1; Hongxu Li1; Liangtian Wei1; Chao Li1; Shi Sun1; Zhaobo Liu2; 1University of Science and Technology Beijing; 2University of Science & Technology Beijing
    Aiming at the recovery of copper from smelting slag, a flotation approach was studied. It was found that this slag composed of fine particles with complex association and distribution, in which bornite was the main copper-bearing mineral after a detailed mineralogy analysis via polarizing microscope, SEM and XRD. Consequently, flotation was attempted to recycle Cu in slag containing copper sulphide components. Three key factors affecting flotation were ascertained, namely, grinding fineness, the collector and the pH value, while the recovery of Cu estimated by ICP and XRF. Copper concentrate grading at 14.47% with 79.66% Cu recovery was obtained, in the condition of the grinding fineness of -0.074 mm and the proportion of 80%, reagent dosages of 50 g/t for butyl xanthate and a pH value of 10 adjusted using Na2CO3.