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By Shijie Wang

Lifetime achievements of Professor Reddy ’s teaching, research and scholarship in the field of chemical and materials science and engineering are briefly described. He has devoted his entire career in the introduction and application of process engineering principles to the quantitative description of materials processing reactions, and industrial operations. He has formulated quantitative methodologies based on first principles of thermodynamics, phase equilibria and kinetics to: design of slags and fluxes for production and purification of metals and alloys; development of Reddy-Blander model for a priori prediction of impurities capacities of melts; development of novel ionic liquid electrolytes for materials processing; development of new theories for alloys and molten salts; design materials for fuel cells and capacitors; use of thermodynamic approaches to predict physical properties of materials; industrial energy waste separation and remediation; and thermal energy storage. He is a scholar and mentor, and has made numerous scientific and service contributions to the society and metallurgical and materials engineering education.

Mar 1, 2017

Gas flow and heat transfer phenomena in two industrial-scale waste-heat boilers of the Outokumpu copper flash smelting process were analyzed with a commercial computational fluid-dynamics (CFD) package Phoenics. Various operating conditions were simulated for the first boiler and particularly for the second boiler. The gas flow pattern was compared qualitatively with the physical laboratory models, and the general flow pattern was consistent with the laboratory visualization. The heat transfer simulation was validated with, temperature measurements for both boilers, and good agreement was reached between the computed temperature profiles and the measured data. The computational results indicate that gas flow in both boilers is of three-dimensional and recirculating nature. The numerical tracer experiments indicate that some dead volume is present in both boilers, and the boiler modification reduced the dead volume from 38% to 15% under basic operating conditions. Radiative heat transfer accounts for 65-90% of the total 'heat transported in the radiation sections of both boilers under different operating conditions. The modified boiler is very efficient for cooling the off-gases at almost doubled volume flow rate. The CFD modeling proved to be a useful tool for numerical experiments and analysis of boiler performance for process: optimization.

Jan 1, 1998

Direct electrowinning is an electrochemical process which has been developed for the extractive recovery of copper from dilute, acidic leach solutions. In passing through a thin particulate coke cathode. copper is reduced and electrodeposited in a thin layer forming a solid copper-coke sheet. The product is melted in a furnace to separate the coke, then the molten copper is fire refined to produce a salable product. A description is given of a prototype unit which is designed to treat 20 gpm leach liquor and recover over 100 pounds of copper per day. Economic analyses show that in a commercial facility producing about 25.000 TPY copper.*the direct electrowinning process has lower overall cost than either conventional iron-cementation or the newer liquid ion exchange-electrowinning when the leach liquors contain less than 2 grams per liter of copper.

Jan 1, 1976

By D. W. Collins

The uptake of gold from halide solutions by activated carbon has been investigated using various techniques. Halide systems typically exhibit combined adsorption-reduction type behavior. In an attempt to gain more information about the nature of these processes, samples of synthetic highly-oriented pyrolytic graphite (HOPG) were contacted with aqueous solutions of gold-iodide. HOPG represents a model structure for activated carbon comprising of basal- plane sites, edge sites, and various defect sites. Two basic instrumental methods were used to examine the uptake of gold by HOPG. The first was standard X-ray photoelectron spectroscopy (XPS). The other involved several scanning probe techniques. XPS clearly indicated a preferred uptake of gold at edge sites. However, iodine appeared to be distributed on both basal-plane and edge sites. At low iodine additions, tapping mode AFM showed that clusters were concentrated along steps and surface defects. At high iodine concentrations, the HOPG surface was uniformly covered by iodine.

Jan 1, 1998

By Michael A. Eamon

Magma Copper Company has operated its San Manuel SX-EW Plant facilities since 1986. The original plant facilities have a design capacity of 25,000 tons per year of electrowon copper cathode produced by processing pregnant leach solutions from an open pit/heap leach operation. In 1988, the plant was expanded to 50,000 tons per year to incorporate processing leach solutions from an insitu leaching operation. This paper presents a general overview of plant practices with particular emphasis on process innovations developed and implemented by Magma during construction and operation.

Jan 1, 1991

By S. W. Marcuson

Smelting of nickel-copper sulfide ores at Vale Inco’s Sudbury operations commenced in 1888 and the first converting plant went into operation in 1892. As the demand for nickel grew, the smelting operations expanded and by the 1960’s the Copper Cliff Smelter featured the longest converter aisle in the world with space for nineteen Peirce-Smith converters. During this long period, different converting techniques and vessels were employed. The evolution of converting is reviewed with special emphasis on the modifications made to the Peirce-Smith vessel to accommodate the metallurgical and process needs of the changing times.

Jan 1, 2009

By Mikula Adolf

Lead-tin solders are commonly used in electronic packaging due to their unique combination of electrical, chemical, physical, thermal and mechanical properties. Since it is known that lead and lead containing alloys cause great environmental concern and health hazards it is necessary to replace lead in solder materials. Besides the environmental concerns new technologies in electronic packaging require new and improved solders. In most cases the new solders will consist of temary or quarternary alloy systems, the main component will be tin or indium and the second element could be bismuth. silver, copper and gold and to improve certain properties a third element will be added. For a third element zinc, nickel, antimony and aluminum can be considered. This report will concentrate on solders containing zinc as an environmental safe. element.

Jan 1, 2003

By Dietrich Gross

This paper describes an advanced oxy-fuel combustion technology for re-melting aluminum that significantly reduces energy consumption and emissions. This oxy-fuel combustion technology developed by Jupiter Oxygen is a patented process for combustion of fossil fuels with pure oxygen while excluding air, thereby creating an undiluted high flame temperature and increased efficiency for process heating in industrial furnaces. This unique process has led to improved heat transfer and longer residence time while maintaining the same process temperatures as with air combustion. The energy efficient combustion process allows aluminum companies to operate at a substantially lower cost due to a dramatic fuel savings of up to 70% for natural gas and waste oil (1). The results of more than 10 years of day-to-day experience utilizing the Jupiter Oxygen Corporation oxy-fuel combustion technology licensed to Jupiter Aluminum Corporation in the aluminum re-melting business are discussed.

Jan 1, 2008

By Alessandro Navarra, Joël P. T. Kapusta

"The converting cost modeling software introduced by Ng et al. in 2005 [1] has been extended to consider the reprocessing of reverts and copper scrap. The original model evaluated the operational costs of a Peirce-Smith converter; algebraic relationships had been implemented with arrays (to represent matrices, vectors and scalar ratios). The new software brings flexibility to the underlying thermochemical balances, by using linked-lists instead of arrays. It is now possible to consider the blending of several feeds, including reverts and scrap.The software computes the length of the converting cycle from the Fe and S content of the charge together with the blowing rate; the times required for other operations (charging, skimming and idle time) are also accounted for. The costs of consumables such as flux, fuel, oxygen or compressed air are all evaluated. Downtime, labor, and materials for converter lining repairs are also considered. The software is easily extended to examine the costs of alternative operating strategies or injection technologies such as sonic single pipe injection and sonic shrouded injection. The potential cost benefits of alternative operating procedures and technologies are discussed through example calculations."

Jan 1, 2009

By D. J. Webb, D. G. Reynolds, D. W. Ashman, D. W. Goosen

Cominco Limited operates an integrated zinc-lead complex at Trail, British Columbia, Canada. Central to the successful operation of this complex is the treatment of zinc leach residues through the lead smelter. In 1997, Cominco started up a new lead smelter using KTVCET flash smelting, a state-of-the-art conventional slag fuming furnace, and a new drossing plant. The smelter has fully met the requirements for environmental performance, reduced energy consumption, and lowered labour costs. This paper provides a description of the new smelter and discusses the problems encountered during the start-up, as well as the solutions to those problems. Recent operating results are presented. Lead-Zinc

Jan 1, 2000

By Afshin Sadri

Acousto Ultrasonic-Echo (AU-E) is a technique developed to provide accurate measurements of the refractory lining wear in operating smelters based on the principles of stress wave propagation. The objective of the system is to provide feedback for the continuous optimization of the overall smelter operation. In some cases, the AU-E refractory lining measurements have allowed clients to extend their smelter campaigns and operate safely for several years beyond their planned reline schedule. In other cases, AU-E results inform clients of serious issues within their furnace allowing them to shut down their smelters ahead of predicted failures and possible disasters. This paper presents the results of several smelter AU-E inspections of the hearth and sidewall. These case studies demonstrate how the AU-E results were used to positively affect the smelter operation.

By D. Donald Downey

Pilot Testing Ion Exchange Resin (IEX) can go from very simple beaker testing to complicated column testing. Space velocities, regenerant quantities, loading capacities, ion leakage, are all terms that get accumulated together to prove or disprove a resin’s (or resins’) ability to load a single ion (or specific set of ions). Not getting all the resin’s operating parameters correct will disqualify (or at least skew) the results. Laboratory tests for capacity, moisture content, bead size, metals fouling, etc.—what does it all mean? At last count, there were over twenty-five separate ion exchange resin tests (analyses) that were available to end users. Standard testing procedures identify the resin properties but more specific procedures can be used to identify problems with equipment operation. Then, there are the costs to consider; simple cation resin testing (moisture content, total capacity and bead integrity) is in the $200/sample range. However, add to this Chatillon, Russian Ball Mill Test, HIAC particle size, metals and % regeneration test procedures and the lab work can increase to over $1000/sample. In this paper, the author will explain the “must-do” pilot and test procedures and why they are important and the key to understanding how resin performs ion exchange.

By A. S. Usrnani

Due to both turbulence and the highly variable geometry of castings, a realistic numerical simulation of the metal flow is prohibitvely expensive with current technology. However, when the chief purpose is to achieve realistic thermal fields a precise How simulation is not necessarily required. In this paper we assume a laminar flow regime and obtain the flow field by solving the incompressible Navier-Stokes Equations using a velocity-pressure segregated semi-implicit finite element method. The free metal surface is predicted by advecting a pseudo-concentration function via the computed How field. This involves an explicit finite element solution of a pure advection equation. The thermal field is calculated by solving the convective-diffusive energy equation by an explicit finite element method using the computed flow field and the location of the free surface. All the advection terms are discretized using a Taylor-Galerkin method. The interface between the metal and mould is modelled using special interface elements. The model is demonstrated by solving practical example problems. The results show that a sharp thermal front is maintained during the course of filling without excessive diffusion. The heat diffusion in the mould can be controlled by varying the metal mould heat transfer coefficient.

Jan 1, 1994

By Darrin Wikoff

"The data, compiled by the Department of Energy (DOE), indicates that the average industrial plant could reduce its total energy cost by 14.8% by implementing effective Life Cycle Asset Management processes. The actual savings varies by industrial classification, but in all cases the potential is substantial and could have a marked impact on the operating profit of the company.Improvements geared towards improving equipment reliability have distinctive linkages to environmental performance, such as reducing the amount of product and raw material waste through routine monitoring of system parameters through predictive technologies, and preventing interruptions to production cycles with a focus on Overall Equipment Effectiveness (OEE).Alcoa successfully reduced solvent disposal costs by more than 40% and GE reduced greenhouse gas emissions by more than 250,000 metric tons. This presentation will show you how companies have successfully reduced energy and disposal costs through a focused effort on manufacturing process reliability.IntroductionSmelter in the ParkThe quaint town of Portland, Victoria protrudes outward towards Antarctica from Australia’s southeastern coastline. Portland is a quiet rural community surrounded by agriculture that draws tourists by the thousands to the southernmost edge of Victoria by way of breathtaking cliff top views of the majestic Southern Ocean, the intrigue of shipwreck coves along the Great Ocean Road, and what most will call the eighth wonder of the modern world, the “Smelter in the Park”. Integrated within Portland’s beautiful landscape is a 356,000 ton/year aluminum smelter that stands as a symbol of collaboration between nature and industry. Nestled atop a ridge which faces “Sail Rock”, a popular destination of local and visiting fisherman, the smelter is engulfed in a mix of brush and wetland preserves that are home to many of Australia’s feathered and fourlegged natives. Also within its interior you’ll find parks and natural landscapes abundant where man and machines coexist with the native inhabitants."

Jan 1, 2009

By Du Sichen, S. Seetharaman, A. Jakobsson

"In the Present paper, the principles of oxygen potential measurements have been discussed along with the design details for oxygen sensors that are used in copper industry. A description of some of commercial probes is presented along with their salient features. The application of these sensors in flash smelting, converter and casting sections of copper production are discussed along with their implications on process optimization.I. IntroductionThe high temperature galvanic cells have come into prominence on account of their numerous applications in both fundamental as well as applied measurements. Since the inception of the oxygen-ion conducting electrolytes like ZrOrCaO·by Kiukkola and Wagner [1], the oxygen concentration cells have been extensively used in laboratories as well as in industries. In metal-production technology, these cells have been used to monitor the oxygen potentials in metallic, slag as well as gas phases and also to control and styr metallurgical processes. The pioneer among the various industrial users of such cells is the copper industry. To-day, high temperature solid electrolyte cells involving oxygen ion conducting electrolytes have become an integral part of copper pyro-refining and continuous casting. In the present paper some of the applications according to the industrial processes are described including the developments that are going on in the European scene."

Jan 1, 1997

By Xin Li, Zurui Hu, Fuming Zhang

High blast temperature is one of the important technical characteristics of modern blast furnace (BF), which is also an important technical approach for the green development of ironmaking. Increase blast temperature can improve and promote the BF operation smooth and stable, reduce coke rate, fuel consumption and CO2 emission. Top combustion hot blast stove technology has been applied in Shougang Jingtang’s 5500 m3 BF for 8 years. Under the condition of burning single BF gas, high efficiency energy conversion and over 1250 °C high blast temperature have achieved. The combustion and heat transformation process were researched by numerical simulation technology to optimize the structure design. The high efficiency annular ceramic burner and checker brick were developed and applied, the flue gas waste heat was recovered and reused to preheat the combustion air and gas. Prominent achievement of high blast temperature under the condition single BF gas burning has been realized.

Mar 1, 2018

By Hu Long

In this, the first systematic study of the oxidation of orpiment (As2S3) in sulfuric acid solution under oxygen pressure at temperatures above 170°C, the effects of retention time, temperature, particle size, oxygen partial pressure, the concentration of sulfuric acid and pulp density were evaluated. The effects of cupric and ferric ions on the oxidation rate of As(III) to As(V) were also examined. The products of oxidation are As(III), As(V), SO42- and elemental sulfur. At temperatures ranging from 170 to 230°C, most of the arsenic was found to be in the trivalent state, and oxidation to As(V) with oxygen was very slow. This was confirmed by attempting to oxidize a synthetic arsenious solution. However, the rate of oxidation of As(III) to As(V) is rapid in the presence of ferric ion. Elemental sulfur was found at all temperatures investigated, which can be further oxidized to sulfate at high temperature.

Jan 1, 1999

By Rodney Clary

Building on work completed in earlier papers, the current paper presents a techno-economic evaluation of two recently demonstrated technologies for treatment of arsenic containing refractory gold concentrates. Using defined project parameters and inputs, the authors compare capital and operating cost estimates for pressure oxidation (POx), and the Albion Process™. The paper incorporates data now publicly available from the Albion Process™ plant, which has operated at the GeoProMining Gold (GPM Gold) project in Armenia since 2014, as well as recent POx circuits.

By Vinicius Alves Gomes, Jean Igor Margem, Thallis Cordeiro, Frederico Muylaert Margem, Roberto Faria Jr., Sergio Neves Monteiro, Marina Rangel Margem

Natural fibers are attracting the interest of engineering sectors owing to specific advantages such as lightweight and lower cost as well as for their inherent condition of being renewable, biodegradable, recyclable and neutral with respect to CO2 emission. In particular, the fiber extracted from the malva plant stem is nowadays recognized as one of the strongest lignocellulosic fibers. However, the thermal properties of the malva fibers have yet not been fully investigated. The present work had as its objective to investigate, by photoacoustic spectroscopy and photothermal techniques the thermal properties of diffusivity, specific heat capacity and conductivity of a pressed malva fibers sample. The results revealed that these fibers showed a superior thermal insulation capacity.

Jan 1, 2015

By Theodore Ineich

The “BIOMOre” project aims to prove the technical feasibility of indirect in situ bioleaching of sulfide minerals contained in a deep underground deposit, by bringing together the disciplines required to make a success. The underground location in Poland was provided by project partner KGHM inside an operating copper mine. Key components of this project were the design and construction of a pilot plant, and its operation in an underground environment. This project also included a ∼250 t (100 m3) fragmented rock reactor hydraulically connected to the pilot plant. The pilot plant consisted of several tanks and pumps, a fluidised bed ferric iron generating bioreactor containing immobilised acidophilic iron oxidation biomass, and all the required instrumentation and utilities. Before the bioleaching phase could start, the rock reactor had to be flushed continuously firstly with water to remove chloride salts that are corrosive and also harmful for the bacteria used in the bioreactor, and secondly, with sulfuric acid solution to react with the carbonates present in the ore matrix. This paper summarizes the design, construction, commissioning, and operation of the pilot plant.