NML's Activities on Non-ferrous Metals Extraction

India is not well endowed with high grade deposits of ores and minerals of nonferrous metals except bauxite ore of aluminium and beach sand containing titanium, zirconium, and rare earth metals. Hence, the National Metallurgical Laboratory, Jamshedpur, which was first laboratory in the country established to cater the need for developing metal extraction processes, had to concentrate on the beneficia-tion of available lean grade ores of non-ferrous metals and the extraction of valuable metals from the concentra-tes, industrial wastes and secondary resources. This paper briefly mentions the technologies developed, infrastruc-ture and facilities established and the current activities in the field of non-ferrous metal extraction in the labora-tory

A thermochemical dynamic model of a Top Submerged Lance furnace: Experimental validation with focus on minor elements for the Circular Economy

The trend towards a more circular economy presents a unique challenge for the pyrometallurgical engineer. Secondary feeds bring complexity to the smelter in the form of non-traditional chemistries and minor elements. Models of furnaces will play an important role in this paradigm. Models should be able to predict operations in dynamic systems that do not always operate at equilibrium.The development of a top submerged lance (TSL) model was the subject of this study because the TSL has proven to be capable of treating secondary materials.The furnace consists of a vertical cylindrical vessel, containing molten slag and bullion at the bottom. A lance enters through the roof and the tip is submerged in the slag, into which gas and fuel are blown. Secondary or primary feeds, fluxes and reductants can be fed to the furnace. The reactions and interplay between the liquid phases, gas and added reductants set the temperatures and partial oxygen pressures in the furnace. The Connected Local Equilibria (CLE) method was followed to model the furnace. This approach offers the benefit that speciation can be modelled simultaneously for many elements from thermochemical databases. The methodology is to divide the furnace into several equilibrium volumes, based on expected material flows. With each time step, equilibrium in each volume is calculated by Gibbs free energy minimization. Material is then exchanged between volumes according to expected flows. To validate the method, small scale crucible experiments were carried out. Molten lead-containing ferric calcium silicate slags (PbO-FCS slag, also containing GeO2, TeO2 and SnO2 in concentrations ˂ 1 wt%) were reduced under controlled CO/CO2 atmospheres to produce lead bullion. The kinetics of the process were measured. Similar experiments were carried out with a copper-containing ferric calcium silicate system. The CLE method was applied to simulate the data, using HSC Sim software. The crucible was divided into four equilibrium volumes: slag-gas contact; slag; slag-hearth contact; hearth. The gas flowrate to the slag-gas contact was determined by following a rate-law in the form of chemical reaction control (e.g. Rg-s = kapp.pCO (mol O.cm-2.s-1)). By using a single fitting factor (kapp), the dynamic behaviour of lead and the minor elements (tin, tellurium, germanium) could be predicted. The same method was successfully used for the CuO-FCS system. The use of this method enhanced understanding of the experiments, by showing the component speciation during reduction. Full-scale TSL models were then developed using HSC Chemistry software and SimuSage software. In both cases the CLE method was applied. The flow patterns in the furnace were gleaned from published computational fluid dynamics (CFD) work. The interface areas were not known, and assumptions thus needed to be made to model an industrial process for lead-oxide FCS slag reduction. It was shown that the model can provide useful insight into real-world problems. Two branches of modelling might develop from this work. In one, CFD work can quantify interface areas in the furnace, so that CLE models similar to the current work are possible. In the second, only bulk fluid movement might be used. In either case, this work validates the approach of using a thermochemical approach to model kinetics.:1 INTRODUCTION 1.1 THE METALLURGICAL CHALLENGE TO ACHIEVE A CIRCULAR ECONOMY 1.2 APPLICATION OF UNIT MODELS IN TECHNO-ECONOMIC, EXERGY AND ENVIRONMENTAL FOOTPRINT ANALYSES 1.3 FOCUS OF THE CURRENT WORK 2 RESEARCH OBJECTIVES 3 LITERATURE REVIEW 3.1 LEAD METALLURGY (INCLUDING WEEE) 3.2 COPPER METALLURGY 3.3 EQUILIBRIUM BEHAVIOUR OF MINOR ELEMENTS IN LEAD AND COPPER METALLURGY 3.4 SLAG REDUCTION KINETICS 3.5 TSL FURNACE 3.6 MODELLING OF BATH-TYPE SMELTERS 3.6.3 CFD Modelling 4 EXPERIMENTAL METHODOLOGY 4.1 MASTER SLAG PREPARATION 4.2 EXPERIMENTAL SETUP 4.3 REDUCTION EXPERIMENT PROCEDURE 4.4 LIST OF EXPERIMENTS 4.5 ANALYTICAL METHOD 4.6 REACTION OF SLAGS WITH CRUCIBLE WALLS 5 EXPERIMENTAL ERROR EVALUATION 5.1 ERROR IN MASTER SLAG COMPOSITION MEASUREMENTS 5.2 REPEAT TESTS 5.3 EXPERIMENTAL ERROR 6 MODELLING OF KINETICS WITH HSC SIM 6.1 HSC CHEMISTRY DYNAMIC MODULE AND CONNECTED LOCAL EQUILIBRIA MODELLING 6.2 RESULTS FOR MODELLING LEAD EXPERIMENTAL RESULTS WITH HSC CHEMISTRY 6.3 RESULTS FOR MODELLING COPPER EXPERIMENTAL RESULTS WITH HSC CHEMISTRY 7 TSL MODEL IN HSC CHEMISTRY 7.1 FLUID FLOW IN TSL FOR CONNECTED LOCAL EQUILIBRIA MODELLING 7.2 TANKS AND OPERATIONS IN HSC SIM MODEL 7.3 EXAMPLE OF HSC SIM CLE MODEL APPLICATION 8 TSL MODEL ON SIMUSAGE PLATFORM 8.1 METHOD FOR SIMUSAGE MODEL 8.2 SPECIES SELECTION IN SIMUSAGE MODEL 8.3 EXAMPLE OF SIMUSAGE CLE MODEL APPLICATION 9 COMPARISON OF HSC SIM AND SIMUSAGE RESULTS 10 CRITICAL ANALYSIS OF MODEL METHODOLOGY 10.1 MEASUREMENT OF BULK VOLUME COMPOSITIONS 10.2 HEAT TRANSFER IN HSC SIM AND SIMUSAGE MODELS 10.3 USING BULK FLUID FLOWS VS INTERFACE APPROACH 11 CONCLUSIONS 11.1 MOTIVATION 11.2 LABORATORY KINETIC MEASUREMENTS AND MODELLING WITH CLE METHOD 11.3 TSL MODELLING WITH HSC SIM AND SIMUSAGE 12 REFERENCE

Fundamental aspects of alloy smelting in a DC arc furnace

DC arc furnaces have been applied to a number of smelting processes, including the reductive smelting of chromite ore fines to produce ferrochromium, the smelting of ilmenite to produce titania slag and pig iron, the recovery of cobalt from non-ferrous smelter slags, stainless steel dust smelting, battery recycling, and nickel laterite smelting. The recovery of base metals and platinum group metals (PGMs) in a reductive smelting process is a function of the recovery of iron (which indicates the extent of reduction). A recovery equation has been developed that is characterised by a single parameter (Ky) for each metal that can either be fitted empirically to the data, or expressed in terms of the equilibrium constant and the ratios of the activity coefficients involved. The DC arc furnace has been modelled electrically as an arc in series with a layer of slag. The voltage is non-linear with respect to the current. Equations have been developed (and confirmed by measurement) to describe how the arc voltage varies as a function of arc length and current. The voltage distribution across a molten slag bath requires the solution of Laplace’s equation for a geometry that includes the depression in the molten slag caused by the impingement of the arc jet. Aspect ratios of the arc depression were determined photographically. Equations have been developed for the calculation of the mean residence time in a continuously-fed batch-tapped furnace, and this has been illustrated using a novel graphical depiction. The mean residence time is directly proportional to the tap-to-tap time, and is increased by increasing the volume of material retained in the furnace between taps. The ConRoast process treats dead-roasted nickel sulfide or PGM concentrates by reductive smelting in a DC arc furnace, where an ironbased alloy is used to collect the valuable metals. This process results in much lower sulfur dioxide emissions, the ability to accept high chromite contents, and improved furnace containment. The ConRoast process has been demonstrated by smelting 50 000 tons of PGM-containing feed materials at Mintek over a period of operation of about five years

Annual Report 1971-1972

It contains the statement of R&D works undertaken, achivement made and the expenditure by the laboratory during the financial year 1971-1972

Phytoremediation of polluted soils : recent progress and developments.: Phytostabilisation of a copper contaminated topsoil aided by basic slags: assessment ofCu mobility and phytoavailability

International audiencePurposeBasic slags are alkaline by-products of the steel industry with potential properties to ameliorate nutrient supply and metal stabilisation in contaminated soils. This study aimed at investigating the potential of a P-spiked Link Donawitz slag and a conventional basic slag called Carmeuse for the aided phytostabilisation of a Cu-contaminated soil at a wood treatment site. The effects of basic slag addition on Cu fractionation, mobility and (phyto) availability were assessed.Materials and methodsBoth slags were incorporated at 1 % w/w into the Cu-contaminated soil phytostabilised with Cu-tolerant plants, using either outdoor lysimeters or a field plot. Untreated soil (UNT), amended soils with the P-spiked Link Donawitz slag (PLDS) and the conventional slag (CARM) respectively, and a control soil (CTRL) were sampled, potted and cultivated with dwarf bean. Physico-chemical analysis, determination of total soil elements and a Cu-sequential extraction scheme were carried out for all soils. Physico-chemical characteristics of soil pore water and Cu speciation (rhizon, ion selective electrode and diffusive gradient in thin film (DGT)) were determined. Shoot dry weight yield and leaf ionome (i.e. all inorganic ions present in the primary leaves) of dwarf beans were investigated.Results and discussionThe slag incorporation at only 1 % w/w increased the soil pH from 1.5 to 2 U and electrical conductivity in soil pore water by three times. The residual Cu fraction increased for both slag amended soils compared to the UNT soil by six times in parallel to the decrease of the Cu oxidisable fraction (1.5 times) and to a less extent the reducible fraction. The incorporation of both slags did not reduce the total dissolved Cu concentration in the soil pore water but significantly reduced the real dissolved Cu concentration ca five times, the Cu labile pool as measured by DGT (at least two times) and the Cu phytoavailability. The dwarf bean total biomass was also improved with the slag addition especially for the P-spiked Linz–Donawitz slag.ConclusionsThe addition of both slags in the contaminated soil increased Cu concentration in the residual fraction and thus reduced its potential mobility. Though the total dissolved Cu soil pore water concentration remained identical, its speciation changed as the real dissolved fraction diminished and lowered the Cu bioavailability. The addition of small amount of P-spiked Linz–Donawitz and Carmeuse slags was beneficial for this Cu-contaminated soil in the context of aided phytostabilisation

Annual Report 1973-1974

It contains the statement of R&D works undertaken, achivement made and the expenditure by the laboratory during the financial year 1973-1974

Book of abstracts of the 15th International Symposium of Croatian Metallurgical Society - SHMD \u272022, Materials and metallurgy

Book of abstracts of the 15th International Symposium of Croatian Metallurgical Society - SHMD \u272022, Materials and metallurgy, Zagreb, Croatia, March 22-23, 2022. Abstracts are organized in four sections: Materials - section A; Process metallurgy - Section B; Plastic processing - Section C and Metallurgy and related topics - Section D

Book of abstracts of the 15th International Symposium of Croatian Metallurgical Society - SHMD \u272022, Materials and metallurgy

Book of abstracts of the 15th International Symposium of Croatian Metallurgical Society - SHMD \u272022, Materials and metallurgy, Zagreb, Croatia, March 22-23, 2022. Abstracts are organized in four sections: Materials - section A; Process metallurgy - Section B; Plastic processing - Section C and Metallurgy and related topics - Section D

Processing of Anthropogenic Waste of Smelters of the Ural Mining and Metallurgical Company

The industrial sites of the smelters of the Ural Mining and Metallurgical Company have accumulated a lot of anthropogenic waste, the processing of which is currently economically impractical. These primarily include tailings and beneficiation tailings, as well as waste granulated and copper smelting slag. This article conducts studies on technologies for x-ray-radiometric/magnetic separation enrichment of discard slags of MMSK as well as using jigging machines. Slag and slag enrichment tailings are used for cement production and road construction. For complex processing of fine copper smelting dusts OJSC Chelyabinsk zinc plant developed, tested and implemented a special technology. After implementation of ”Actions to process industrial waste generated by UMMC enterprises at metallurgical enterprises of UMMC-Holding Corp.”, the following were noted: concentrators and special beneficiation facilities process slag; R&D on complete processing of concentrator’s tailings was conducted; smelting dust was not stored but processed in full; the technology of implementing Waelz process for processing of steel smelting dust has been developed and commercially tested; the technology for extraction of copper and precious metals from pyrite dross is to be improved. Keywords: anthropogenic waste, dust, tailings, slag, pyrite dros

DEFINICJA OBIEKTÓW WIELOWYMIAROWEGO STEROWANIA PROCESAMI TECHNOLOGICZNYMI W HUTNICTWIE NA PODSTAWIE MODELU OPTYMALIZACJI

This article analyzes work of metallurgical shop as a complex control object. It also includes description of copper complex and synthesizes three-level structure of control system. Technical and economical indexes and also control object are defined in this article.W artykule przedstawiono analizę pracy przemysłu metalurgicznego rozpatrywanego jako złożony obiekt sterowania. Opisano kompleks hutniczy i syntetyzowaną trójwarstwową strukturę systemu sterowania. Określono wskaźniki techniczno-ekonomiczne i sformułowano zadania sterowania