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By F. Baldini, M. S. Borges

"The proposed method emphasizes the optimization of waste management with regard to the exploitation of raw materials incorporated in the remains of industry, as well as the economics of natural resources as an environmental impact assessment. This system [tool] allows: (a) the conversion of an environmental liability into an asset by finding a line of appropriate research for each type of waste and the development of new materials applicable to other industries, (b) the performance of internal control of the waste generated (production, storage, final destination) as well as legal conformity.Objectives:1.1 General objective:To design a collaborative system for socio-environmental management of industrial waste.1.2 Specific objective:Develop evidence of concepts;Evaluate the deployment of the inventory of waste in an industry;Enable the conversion of an environmental liability into an asset by finding a line of research appropriate to the waste: a case study;Evaluate the environmental legislation in the legal mechanisms that influence company decisions.IntroductionThe global economy is undergoing major changes, among these changes; it should be highlighted those related to technological progress and environmental quality.While the industrialized countries and higher levels of economic growth dominate modem technology, developing countries are identified by a different growth pattern, using the annual growth rate of Gross Domestic Product per capita [3, 18].Growth is when the GDP grows, in percent, over the previous year. Development, on the other hand, is when the countries change their technologies and improve their internal structure. Thus, the growth considers the accumulation of wealth, while the development is concerned with the distribution of wealth, improvement of the quality oflife and environmental quality [3, 18].As the UNESCO report shows (1999), the biggest problem is between consumption and development, what is produced and the end that is given to the product. Therefore, product and by-product have equal importance in the quantity produced [29].On one hand there is a positive relationship between indicators of economic growth and technological progress, however, on the other hand, these transformations are a paradox, confirmed by the dramatic use of environmental resources and the lack of technologies for recycling of industrial scrap."

Jan 1, 2011

By D. E. Karvelas

Argonne National Laboratory is conducting research to develop a cost-effective and environmentally acceptable process for the separation of high-value plastics from discarded household appliances. The process under development has separated individual high purity (greater than 99.5%) acrylonitrile-butadiene-styrene (ABS) and high-impact polystyrene (HIPS) from corruningled plastics generated by appliance-shredding and metal-recovery operations. The process consists of size-reduction steps for the commingled plastics, followed by a series of gravity- separation techniques to separate plastic materials of different densities. Individual plastics of similar densities, such as ABS and HIPS, are further separated by using a chemical solution. By controlling the surface tension, the density, and the temperature of the chemical solution, we are able to selectively float/separate plastics that have different surface energies. This separation technique has proven to be highly effective in recovering high-purity plastics materials from discarded household appliances. A conceptual design of a continuous process to recover high-value plastics from discarded appliances is also discussed. In addition to plastics separation research, Argonne National Laboratory is conducting research to develop cost-effective techniques for improving the mechanical properties of plastics recovered from appliances.

Jan 1, 1996

By M. Pakala, Z. Fan, Ray Y. Lin

Deposition of hard chromium coatings using electrodeposition is accompanied by emission of hexavalent chromium mists which is a carcinogenic. Hence alternative chromium deposition technologies are being investigated. Sputter deposition is a strong candidate to economically deposit hard chromium coatings in an environmentally friendly way. Chromium coatings of 2-3 µ m thickness were deposited on plain carbon steel coupons using RF magnetron sputter deposition. Depositions were carried out with 0 to 22 vol% nitrogen in the plasma. Structure of the coatings was studied using x-ray diffraction analysis With increasing nitrogen contents, formation of the two nitride phases was observed. The pure chromium phase was detected in coatings with up to 7% nitrogen in the sputtering gas. The solid solution of nitrogen in the pure Cr phase coating was identified by shifts of Cr x-ray diffraction peaks to higher d-spacing. The microhardness of the coatings deposited at a substrate temperature of 200°C showed an increase in hardness with increasing nitrogen content from 600 kgf/mm2 (5.9 GPa) at 0% nitrogen to I250 kgf/mm2 (I2.25 GPa) at 9.5 % nitrogen and a subsequent decrease in hardness to I 100 kgf/mm2 (11 GPa) beyond 9.5 % nitrogen in the sputtering gas. This corresponds to the formation of the hard Cr2N phase, at 9.5 % nitrogen, and CrN phase, at I5.7 % nitrogen. The reported bulk hardness values of Cr2N and CrN are I600 kgf/mm2 (I5.7 GPa) and I 100 kgf/mm2 (11 GPa) respectively. For pure Cr phase coatings, there is a slight increase in hardness for coatings deposited at 7. I % nitrogen from that without nitrogen in the sputtering gas. This could possibly result from the solid solution strengthening of the Cr lattice by nitrogen. For films deposited at 200°C, phases of the deposited films seem to be the overwhelming factor in controlling the microhardness.

Jan 1, 1998

By Rajesh K. Mishra

The person in charge of Environmental Affairs in a small business has many higher priority projects (such as making money to meet the employee? payroll etc.) than filling out and filing the regulatory forms. It is but. natural to think that these affairs can be managed? by playing ignorant until audited by the regulatory -state and federal agencies. Truth is to. the contrary; generally, it is too late by then. The fines and legal costs even for failing to file the regulatory forms could deliver a serious blow to the financial well-being of a small business. Forms and reports under SARA Title III are not hard to complete., but they are time consuming. In this paper we will discuss the information and data compilation procedures, simplification of some legal terminology into simple technical language, and tips that help in filling out the forms?. Some actual case 'histories of EPA fines will also be reviewed.

Jan 1, 1992

By Torma A. E.

Biotechnological processes are considered to be cost effective especially for situations where the recovery of metals from 'Very large volumes containing trace metal concentrations (less than 10 ppm) is concerned. Microorganisms, alive or dead, or their products can be highly efficient and selective biosorbents for metal concentration. It is important that the metal bound to the biosorbent can be stripped by suitable agent(s) and regenerated for repeated use. The stripped solution should be concentrated enough to be introduced into the common metal recovery circuit. The industrial acceptance of biosorption processes is dictated by increased competitive advantage over other processes. This paper reviews the pertinent literature?, regroups the information, and points out future possibilities for the mineral and metal processing industries.

Jan 1, 1992

By Yury Kapelyushin

Formation of cementite in the reduction of hematite by CO–CO2 gas was studied in situ using high temperature XRD (HT XRD) analysis. Reduction of hematite was examined in the temperature range 873–1173 K by CO–CO2 gas mixture with high carbon activity. When carbon activity in the system was 1.5, cementite was formed only at 1023 K; it was not observed in experiments at 973, 1073 and 1123 K. Formation of cementite was observed at 923–1073 K when carbon activity increased to 3–5; and at 873 K when carbon activity was 10. Formation of cementite at 973–1073 K proceeded through metallic iron; however, in the reduction of hematite at 873 and 923 K, iron was not observed; cementite apparently was formed directly from wüstite. XRD spectra were used to estimate concentration of carbon in austenite in the process of cementite fromation.

By L. M. Luckevich

Gypsum is a product from the neutralization of sulfuric acid by lime or limestone. This paper will discuss specifications for gypsum used in wallboard, cement and agriculture and the factors affecting its utilization potential. Process conditions during the neutralization which enhance or inhibit utilization potential will be included. In addition, this paper provides a technical and economic perspective of the gypsum industry in North America with a view to the factors affecting the utilization of synthetic gypsum in traditional applications. Current production and consumption of natural and synthetic gypsum in Nonh America are described and the impact of their differences on utilization options are discussed.

Jan 1, 1996

By A. O. Apata, F. V. Adams

The use of rice husk ash as aggregate for foundry sand mould production has been studied. 5 –25wt% rice husk ash was added to the sand mixture. The chemical, physical and mechanical properties measured include: chemical analysis of the rice husk ash, particle size, density, permeability, compatibility mouldability, moisture content, green compression and shear strength, dry compression and shear strength. The result revealed that, addition of rice husk ash to River Niger Silica sand, increased the mouldability, compatibility, grain fineness number, both green and dry strength, slightly decreased the density, permeability and moisture content. The result shows that better properties is achievable by the addition of rice husk ash to River Niger silica sand and can be used to enhance the mould properties of foundry sand.

Mar 1, 2017

By Michael J. McGuire

Rostoker, Inc. has developed a process to smelt solid hazardous/non-hazardous inorganic wastes. Near seven hundred experiments were performed. Actual industrial wastes as well as reagent grade chemicals were used. By mixing a multiplicity of these wastes to proper formulations, then furnacing them, it was determined that saleable end products could be reclaimed; metal, fume and slag. The slag, due to its siliceous structure was tested to be leach resistant (40 CFR). This formed the essence of our patent, #5,180,421 "Method and Apparatus for Recovering Useful Products from Waste Streams". What is unique is that a HTMR (High Temperature Metal Recovery) process has been developed that can treat a multiplicity of wastes within the same furnace. The discussion will include a list of waste streams we have treated, details of proper waste formulation and experimental results.

Jan 1, 1994

By Ling-yun Yi, Yuan-bo Zhang, Bing Hu, Zhu-Cheng Huang, Zhen-yuan Liao

"Nucleation and growth mechanism of iron crystal grain in coal-based shaft furnace direct reduction process by microwave heating were investigated by optical microscope, scanning electron microscope and EDX. The results indicate that microwave has selectivity on various minerals which absorb microwaves. The high temperature in certain area of pellets and thermal stress on the interface of minerals are formed, results in the wustite grain smashed along the joints, and iron crystal grains turned out a spherical shape obviously. The iron crystal nucleus is formed firstly at the edge of wustite, on the interface between grains and in the holes in pellets, and grows gradually while reduction carries on from surface layer to inner core. Microwave heating promotes the rate of transportation and accumulation of the iron crystal grain, increases growth rate of iron crystal grain and contributes to formation of dense iron-jointed crystal texture eventually.IntroductionMicrowave energy as a new energy, which selectively heating materials through internal energy dissipation, has the advantages of heating uniformity, high thermal efficiency, fast heating, clean and pollution-free compared to conventional heating motheds. Microwave energy also has obvious superiority in increasing productivity. Thus, it has been widely used in many areas, including electronics, food processing, chemical, medicine, environmental protection, and family life etc [1]. As a rapidly developed green metallurgical method, microwave heating also has been widely recognized by areas of grinding, pretreatment, pre-reduction, drying, furnacing, metal extraction, and waste materials processing and utilization. Some research achievements are gradually putting into practice, showing great potential in chemical and metallurgical industry [2-3]."

Jan 1, 2011

By A. Deneys

An experimental technique has been devised for studying the reaction kinetics of the reaction: ZnO + 2Fe0 = Zn(g) + Fe203, by which zinc evolution can occur from a molten slag bath in the absence of a carbonaceous reductant. When studying the reaction kinetics by heating from room temperature, solid state reactions and poorly defined melting points may obscure the starting point of the reaction. In order to eliminate this problem, an experimental technique was devised whereby two molten slags could be melted independently, and then mixed, to provide a well defined starting point from which to begin taking measurements. Two crucibles were mounted in a vertical reaction cylinder. The upper, mild steel, crucible had a bottom pouring plug which was sealed by a steel stopper rod. A fayalite mixture was contained in this crucible. The lower crucible contained an A12O3-CaO-SiO2-ZnO solution. Once the two slags had been melted, the steel stopper rod was removed from the upper crucible. The upper, reduced slag (fayalite in equilibrium with the upper steel crucible), drained into the lower crucible where the two slags were mixed by submerged argon stirring. Dip samples were taken to measure the zinc content of the final mixture as a function of time. The experimental procedure will be described, as well as results of experiments which were conducted on synthetic slags. The system investigated was similar to the lead blast furnace slag which is produced by the primary lead smelters of Missouri, USA.

Jan 1, 1997

By S. Rick Gilbert

In the course of producing a final metal product, smelters, refineries, and other metallurgical facilities produce wastes which often come under the ?scrutiny of Federal and state regulatory agencies. Many of these wastes contain combinations on zinc, copper, lead, cadmium, nickel or other metals. Frequently in the form of reverts, dusts, or sludges, these metal-containing wastes are often buried in a landfill or speculatively accumulated for future action. Environmental liability can be reduced in many cases by selecting,-a recycling facility which can re-process the waste for.' metal recovery. Encycle, at its hydrometallurgical facility Corpus Christi, has Successfully processed a variety of metallurgical by-products and wastes and returned those contained metals to commerce.

Jan 1, 1995

By Brajendra Mishra, Mark L. Strauss, Gerard P. Martins

Europium is a critical material required for LED, florescent lamp, cell phone screen, and flat panel display production. This process recycling europium from waste lamp phosphors is an innovative method to supply europium. The selective reduction and precipitation method using sulfate precipitation is investigated to recover high-purity europium from yttrium-europium mixed solutions.

Mar 1, 2017

By Yuanbo Zhang, Bin Xu, Guanghui Li, Xiao Kang, Chen Liu, Tao Jiang

Iron-bearing dusts, containing valuable constituents such as Fe, CaO, MgO, C, etc., are generally utilized as raw material in iron ore sintering. However, the dusts characterized by low granulating and refractory performances always lead to negative effects on sintering indexes. As we know, the innovative process named composite agglomeration process (CAP) has a series of advantages compared to traditional sintering process (TSP). In CAP, part or all of the iron-bearing dusts is made into green pellets with 5-15mm in diameter, while the rest of iron-bearing dusts and all of the other fine ores is granulated after mixing with fuels, fluxes and return fines. Compared with TSP, CAP could increase the ratio of iron-bearing dusts from 5% to over 20%. Meanwhile, the yield, ISO tumbler index and productivity reached 75.82%, 65.13% and 1.531t·m-2·h -1, respectively.

Jan 1, 2015

By P. Maraboutis

Iron removal by precipitation as jarosite from Fe-Ni-Co sulfate solutions, (synthetic or real, resulting from laterites leaching) has been investigated. Precipitation was carried out at 95 C, and at an initial pH 1.6, which was either kept constant with CaCO3 or Li2CO3 additions, or left to drift with the evolution of the reaction to lower values. The precipitation of K-, NH4- and Na- jarosite was initially examined using synthetic solutions. In all cases, hydronium ions were incorporated into the precipitate as well. Residual iron in solution was lower (0.2-1 g/1) and equilibrium was achieved faster (within 4-8 h) when precipitating K¬jarosite at constant pH, using CaCO3 for neutralization. Nickel and cobalt losses were small. Na- jarosite precipitation was also studied from real solutions with high initial iron content, under constant pH=1.5, controlled with CaCO3 additions, and it was shown that low residual iron concentration in solution (0.3-0.5 g/1) can be achieved again, with relatively small nickel and cobalt losses. The thickening and filtration characteristics of the precipitates were excellent in all cases examined.

Jan 1, 1988

By Chen Song

In the experiments of purifying the solution of chlorine leaching from nickel concentrate with N235, the effects of organic phase composition on purifying efficiency have been studied. From the results obtained, the optimal organic phase composition is found to be 25%N235+12%isomerous alcohol +63%sulfonic kerosene (VIV) and the saturated content of cobalt in organic phase is7.95 g*dm3. And then the serial experiment is carried out. The results show that at the given organic phase composition, the purified solution contains p(Ni) >200 gm dm3, p(Ni)l p(Co) >50000 and the contents of Cu, Fe, Mn, Zn meet the technical criterion of standard nickel electrolyte. The cobalt chloride solution contains p(Co) >I10 g L-1, p(Co) lp(Ni)>50000 and the enrichment of cobalt has been achieved.

Jan 1, 2006

By Heikki Tuovinen

The total utilization of raw materials and energy is the most important criterion when planning. industrial processes. The main goal is clearly to use the raw materials and energy as effectively as possible in order to make the desired products directly in the primary process itself', or to recycle unused materials and energy either as such, or after cleaning back into the process. However, few industrial processes are so straightforward. Most processes generate by-streams of materials and energy, which cannot be recycled directly and it is namely these by-streams which tend to remain as wastes. These by-streams are slags, dusts, vaporized metals, liquids, slurries, sludges, gases etc. Most base metal processes produce all these by-products. Waste water and gas emission controls and regulations are tightening all the time, so new processes must be developed to keep pace with these requirements. These processes generate more solid wastes, which must be utilized or at least processed into a harmless form landfilling. Municipal and hazardous wastes also contain valuable materials and energy, which must be used to minimize landfilling. The development of processes for these purposes places even greater demands on research and development. The same principles and methods developed for mining, ore dressing and metal refining processes can also be adapted for research and development work on processes for waste minimization. However, the problems encountered are much more complicated and less familiar, demanding more versatile and accurate tools and equipment. This paper presents principles, examples and some references of R & D work on processes for waste minimization.

Jan 1, 1992

By Wenya Du, Qingbo Yu, Peng Li, Qin Qin

"A new heat recovery system is proposed. This system uses the endothermic heat of gasification reaction instead of sensible heat to recover the energy of molten blast furnace slag. The gasification technological parameter in molten blast furnace was calculated and the exergy of the system was analyzed. The gasification reactions were studied kinetically by the isothermal thermogravimetry using STA409PC thermal analyzer. The results showed that, according to different gasification agent, this system can produce syngas with different C-H ratio. The exergy efficiency of this system is high and its internal exergy loss rate is about 11%. This method can bring huge economic and environmental benefits which are important to the survival and sustainable development of iron-steel enterprises. The molten BF slag acts as not only thermal media but also good catalyst. The kinetic parameters on gasification reaction with different types of coal used differ from each other.IntroductionEnergy consumption in the iron-making process is about 50%~60% of the total energy input. The blast furnace is very important in the iron & steel process. So energy conservation and emission reduction about blast furnace is very important. In recent years, in order to recovery energy, many new technologies such as TRT (Top gas pressure Recovery Turbine) and CCPP (Combined Cycle Power Plant) were used in iron-making. But the energy of molten blast furnace (BF) slag has only been used limitedly so far.Molten BF (Blast Furnace) slag is the byproduct of iron-making at the high temperatures range from 1723 to 1923K, and has a large amount of sensible heat remaining. The yield of molten BF slag is about 300 kg per ton of pig iron. In conventional processes, molten BF slag is quenched rapidly using a large amount of water to produce a glassy-granulated slag. The quenching slag must be dried before it can be used in cement manufacture. During the process, a large amount of water was consumed and the energy of molten slag can not be recovered. At the same time, it causes environmental pollution problems. So the critical problems of the process are not only energy recovery of molten slag and reducing emission of H2S and SO2, but also guaranteeing the subsequent use value of slag. For this propose, many new technologies were investigated to recover the thermal energy of molten slag. The promising methods are dry granulation [1-4] and reforming of methane [5-9]. The method, utilization of reaction heat instead of latent heat and sensible heat, is quite attractive from viewpoints of energy storage without heat loss, and makes a connection to other industry. But both of them are in laboratory. In this paper, coal gasification in molten BF slag was used to recover the energy of molten BF slag. The gasification technological parameter in molten BF was calculated and the exergy of the system was analyzed. The gasification reactions were studied kinetically by the isothermal thermogravimetry using STA409PC thermal analyzer."

Jan 1, 2011

By E. M. Weenink

One of the new direct smelting technologies for the production of lead from sulfide concentrates that has reached the commercial stage is the Outokumpu lead flash/electric furnace ?smelting process. Using data from pilot plant test work, energy and mass balances for a commercial plant were initially calculated by hand. To optimize process conditions, a large number of such balances had to be generated and a computer program using Lotus 123 was developed which provided an excellent opportunity for computer simulation. Operating parameters can be calculated by iteration using input values for feed composition, feed rate, smelting temperature, and lead content of the slag'" The output is presented by means of various views of the appropriate process steps, or in 68 different graphs.

Jan 1, 1990

By R. M. Reynolds

Engitec Impianti, S?.p.A. of Milan, Italy has successfully designed, constructed and has in operation state-of-the-art battery breaker systems at two European locations. A third facility i:s partially completed in Toronto, Ontario, Canada. The CX system crushes whole batteries, separates the various components and desulfurizes the battery paste. The system also produces sodium sulfate from the sulfuric acid and lead sulfate contained in the batteries. Actual plant operating data indicates that the desulfurized paste contains less than 0. 6 percent sulfur and less than 0. 5 percent antimony. The CX system utilizes mechanical screening and an up-flow hydrodynamic separator to accomplish the component separation. Sodiwn hydroxide or sodium carbonate is used for desulfurization. The sodium sulfate brine is evaporated and crystallized to produce clean anhydrous sodium sulfate suitable for use by detergent or glass manufacturers. Plant data also indicates that an increase in furnace productivity of about 25 to 30 percent is achieved using feed from the CX system. The desulfurized paste is very suitable for electrolytic processing as an alternative to pyrometallurqical processing.

Jan 1, 1990