Heavy Industry Wastes Utilization
Environmental Technology for the Utilization Heavy Industry Detrimental Wastes through their Recycling in the Manufacturing of Carbon-Thermal and Ceramic Alloys
Tech Area / Field
- ENV-SPC/Solid Waste Pollution and Control/Environment
- CHE-IND/Industrial Chemistry and Chemical Process Engineering/Chemistry
- ENV-APC/Air Pollution and Control/Environment
3 Approved without Funding
Institute of Metallurgy, Georgia, Tbilisi
- Intermas Consultants Ltd., Greece, Athens\nPohang University of Science and Technology, Korea, Pohang\nWestern Michigan University / College of Engineering and Applied Sciences, USA, MI, Kalamazoo\nMichigan Technological University, USA, MI, Houghton\nStockholm University, Sweden, Stockholm
Project summaryObjective of the project is rehabilitation of the environment on the territories around the objects of mining and smelting as well as power industries; ores and igneous rock resources conservation; decrease of the industrial expenses.
Another objective is improvement of ecological conditions and intensification of the technological process of fabrication carbon-thermal alloys and melts for casting of ceramic pieces by using solid wastes of heavy industries, purification of electric ore - thermal furnace (EOTF) gas of CO2 and SO2, and recycling the transformed product into technological cycle.
State of the art in the field. Objects of hard industry, in particular of mining and smelting conversion as well as of energy generation (thermal electro stations - TES), are ecologically most unfavorable, form the point of view of contamination of air and water basins with poisonous metals and compounds. E.g. high concentrations of Mn, Si, Cr and Fe chemical compounds, CO2 and SO2 are the sources of many toxic diseases of humans, animals, plants, inhabitants of aqueous medium and are revealed as "greenhouse effect" or "acid rains." This problem for the environment of Georgia also is very actual. Thus, only in 1992, about 75 t of manganese fell into the r. Kvirila in Western Georgia (where the mining and smelting conversion objects are located). In the last decade, with regard to the general economic crisis in Georgia, mining and processing of manganese ores significantly decreased. In spite of this, however, in urban-industrial and water environments of Zestafoni town (140 km to the west from Tbilisi), an average content of manganese dust and SiO2 notably exceeded maximum allowable concentrations in the year of 2000.
At present there are many progressive technologies for the utilization of solid (among them containing heavy metals) and gaseous detrimental wastes, formed in the process of ore-dressing, high-temperature refining, reduction and combustion. However a problem of qualified utilization of these wastes, stored in a great quantity (as total of millions tons), with the aim of diminishing pollution of the environment and their using in a closed technological cycle is not yet solved. Recycling of wastes in its industry, together with protection of environment has very important strategic and commercial meaning, because it provides safety of ores and igneous rock resources and allows reducing expenses on the manufacturing.
For the solution of the problem of qualified utilization of the wastes it is necessary to elaborate new strategy and approach to the environmental technologies.
In particular, in heavy industry, the aims put by may be reached by elaboration of a new environmental technology on the recycling of solid and gaseous detrimental wastes of mining and smelting, EAF (electric ark furnace), BOF (basic oxygen furnace), EOTF processes, etc. for the metal and ceramic forming allowing broadening materials base, intensifying technological processes and shortening gas emission.
Present project provides elaboration of such a technology, in particular, concerning using of the wastes of mining and smelting conversion such as sludge, slag, EOTF dust, SO2, CO2, in the area of their own production, heavy industry - in the production of carbon-thermal alloys and ceramic casting. Entrapment of TES ash is also provided for ceramic casting.
Novelty and Essence of the Project Elaboration. The new technology is based on the results of investigations and inventions, carried out at the Institute of Metallurgy, Georgian Academy of Sciences for more than 10 years.
Novelty of the project is:
1. To draw solid wastes of heavy industry into the EOTF process as specially agglomerated charges and to transform detrimental components (CO2 and SO2) of EOTF gas of melting of carbon-thermal alloys as bonding material for the preparation the above mentioned charges.
2. To draw solid wastes of heavy industry and TES ash in the ceramic casting process.
Essence of the new technology consists in:
1. Agglomeration of dusty (0,01mm) and small (up to 5 mm) fractions of solid wastes. For such type wastes, in particular, may be used:
- sludge of enriched manganese ores;
- dusty wastes of EOTF process of melting Mn, Si and Cr alloys (world volume of their production being about 20 million ton per year);
- slipped off slag of silicomanganeze of EOTF process;
- TES ash.
2. Cleaning of waste gazes of CO2 and SO2 and recycling of the transformed product into the technological cycle.
For the elaboration of the new technology are to be provided:
1. Investigation and selection of bonding material for agglomeration, having a sufficient mechanical strength at high temperatures and economically approved cost; establishment of the modes of agglomeration (briquetting, pelleting, among them with coating, sintering), establishment of composition and properties of the agglomerated charges; testing of the technology for melting carbon-thermal manganese, siliceous and chromium alloys of EOTF process.
2. Investigation of melts for casting ceramic pieces. These melts will be prepared on the basis of TES ash using manganese-containing wastes. In the technological process will be included the wastes of processing of basalt, andesine, etc. Viscosity, melting temperature, crystallization ability and mineralogical composition of the alloys will be studied.
3. Investigation and modeling of the process of EOTF gas cleaning of СО2 и SO2 through adsorbent and absorbent with subsequent recovery of the routed product into the technological cycle.
4. Environmental monitoring.
Competence of the project team. Project participants are high-skilled specialists in the area of chemical technologies and materials science. In the Former SU they were involved mainly in defense programs. For the recent 10-12 years these scientists participated in the conversion projects, in particular, investigations of environmental chemical technologies. During the above mentioned period more than 40 scientific works were devoted to these problems, among them 9 works were published in the area of technologies attributed to the submitted project. E.g.: 1. “Method and installation for simultaneous definition of shrinkage and electric resistance of charge". Theory and practice of manganese metallurgy. Moscow, "Nauka", 1990, p. 63-73 (T. Chubinidze); 2. “Investigation of adsorption-absorption properties of some natural zeolites". Industry and application of natural zeolites. Baku, 1999, p. 106-111 (T. Kordzakhia); 3. "Using of low-quality and recycled raw material for the melting of Si - Mn - Ca - B - Al - Ti alloy”. Processing of ferrous and manganese ores of South Caucasus. Tbilisi, Georgian Academy of Sciences, "Metsniereba" 2000, p. 102-114 (A. Oakley, T. Chubinidze, D. Jalaghania); 4. “Investigation of the utilization process of low-quality and recycled manganese-containing raw material of mining and smelting and metallurgical conversion”. Problems of Metallurgy, Materials Science and Welding. Tbilisi, GWA, 2002, p. 329-339 (T. Chubinidze, А. Oakley, G. Maisuradze). In 2001- 2002 the participants of the project had contributions two – (A. Mikeladze and G. Maisuradze) at the Republican and two - (А. Oakley and N. Jalabadze) at the International Conferences.
Expected results and their application.
1. Project realization will be resulted in elaboration of a new technology where solid and gaseous wastes of heavy industries as well as TES ash will be involved in the EOTF and ceramic casting processes and technological process will be intensified. There are expected:
1.1. To obtain new basic data on temperature dependence of viscosity of the SiO2-CaO-Al2O3-MgO-FeO-MnO system oxide alloys;
1.2. To obtain new basic data on temperature dependence of electric resistance and charge shrinkage for the production of carbon-thermal alloys with an account of modeling of charge moving process along the EOTF shaft;
1.3. To create a new composition of bonding material, providing stability of the agglomerated raw material against being destroyed at temperatures 1050 – 1400 °С;
1.4. To achieve 100% recycling of dusty wastes of the manufacturing Mn-, Cr- and Si-containing alloys;
1.5. To achieve 20-50% replacement of coke breeze with small-fraction (3mm) coke breeze in the charges intended for production of Mn-, Cr- and Si-containing alloys;
1.6. To achieve 30-70% recycling of SiMn slag in the charges intended for production of high-siliceous (30 -50% Si) manganese alloys and ceramic alloys;
1.7. To achieve 40-60% using of TES ash in the charges for casting ceramic pieces;
1.8. To achieve reduction of CO2 formation in Mn alloys production by 20-25%, without additional purification;
1.9. To make the model of the process of 85% cleaning furnace waste gas of CO2 and SO2, recycling the transformed product into the technological cycle;
1.10. To achieve the 1.5-2.5%- increase of extraction of Mn, 1-2%-increase of extraction of Cr, 2-4%-increase of extraction of Si, 2- 4%-decrease of specific expense of electric power, 2-3%-increase of the output of melting-device.
2. As a result of using new technology will be achieved:
2.1. Practically full rehabilitation of the environment from detrimental influence of solid wastes stored on the territories around the objects of mining and smelting conversion;
2.2. Possibility of economizing ores and igneous rocks resources for the needs of heavy industry, basically on the account of recovery of the wastes of actual industry, i.e. creating of a closed technological cycle;
2.3. 2-4% decreasing of expenses on the production of Mn-, Cr- and Si- alloys; 6-10% decreasing - on ceramic alloys.
Technical approach and methodology. Realization of the project provides fulfilling of new technical solutions and using of modern standard as well as original methods of investigation.
For the elaboration of bonding materials of new composition and choice of optimal charges temperature-dependent surface, electro thermal, and strength properties of agglomerated solid wastes will be studied. In particular, there will be used a new method of simultaneous measuring of electric conductivity and charge shrinkage, elaborated by the project participants. Novelty of the method is that the measurements are provided under influence of increasing loading and temperature. In difference from isodynamic loading, this method allows modeling of moving process of a charge along the EOTF shaft; obtaining of reliable data and taking a proper decision.
Final stage of elaboration of the technology of production Mn-, Cr- and Si-containing alloys with using solid wastes will be realized in the industrial EOTF of JSC “Zestafoni Ferro-alloy works”, basing on the results of the studies of kinetics of appropriate charge reducing processes as well as the tests provided on ore-thermal electric furnace in large-scale laboratory conditions. Data of industrial tests with the account of ecological monitoring will be used for the designing of business plan.
An important role in the elaboration of compositions for casting of ceramic melts based on TES ashes (also containing manganese wastes), will have a study of influence of MnO on the viscosity of the systems SiO2-CaO-Al2O3-MgO-FeO. For the provision of such investigations there will be elaborated a new method based on a proper investigation of tough friction force with automatic registration of temperature dependent data (up to 1800 °C).
Melting point will also be determined by a new method, allowing fixing an interval from the start of melting process up to its completion. Advantage of the method is a simplicity and precision of measurements.
Environmental safety of the ceramic casting process will be achieved through definition of technological parameters of pneumo supply of dust.
Modeling of the process of cleaning EOTF gas of CO2 and SO2 will be realized by using methods of chromatographic, chemical and X-ray analyses. Novelty of the technical solution consists in subsequent influence of absorbent and adsorbent (allowing elevation of cleaning rate) and recovery of the transformed product as a bonding material into the technological cycle.
The ecological monitoring will be carried out under the ISO standards.
Meeting ISTC goals and objectives
The scientific employees that earlier carried out military orders of the Ministry of a Defense Industry, Ministry of an Air Industry and Ministry of Mechanical Engineering of former USSR will be involved in the realization of the project. The support of the project will allow to direct scientific potential of these scientists on realization of researches for the peace purposes (on development of new environmental technology) that allow effective involvement in the production of poisonous solid and gaseous wastes of heavy industry. The technology will be taken to a commercialization stage. Elaboration of the technology will be realized with the minimum expenses if compared with world costs.
The project goals and tasks completely meet national interests of Georgia on the stage of transition to market economy; they are also provisional for solving the problems of science and technology on the international level.
The work embraces 5 tasks, including 2 subtasks and 18 stages which are interconnected in subsequence, starting from the creation of bonding material for agglomeration of solid wastes and finishing with elaboration of industrial technological process with environmental monitoring, identification of potential companies interested in commercialization and making business plan.
New basic data on viscosity and melting temperature of oxide melts of the system (Si, Ca, Al, Mn, Mg, Fe)xOy, electric resistance and shrinkage of the charges will be considered as intermediate results of the project.
Role of foreign collaborators will consist in mutual discussion of reports, comments on the research of technologies, selective cross-control of the investigation results, joints workshops and publications, advices on technology application, identification of potential companies, interested in commercialization of the project and making business-plan.
The International Science and Technology Center (ISTC) is an intergovernmental organization connecting scientists from Kazakhstan, Armenia, Tajikistan, Kyrgyzstan, and Georgia with their peers and research organizations in the EU, Japan, Republic of Korea, Norway and the United States.
ISTC facilitates international science projects and assists the global scientific and business community to source and engage with CIS and Georgian institutes that develop or possess an excellence of scientific know-how.