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Abstract

Content

Introduction

In the problem of rational utilization of industrial wastes the questions of guard of environment and ресурсосбережения were interlaced in a single knot.

An annual economic damage from contamination of environment wastes of production and consumption is estimated at the level of 10% of internal product. Decision of problem of ресурсосбережения in building maybe at the complex use of technical, organizational, economic factors and acceleration of scientific and technical progress.

Major reserve of ресурсосбережения in building is this deployment of secondary material resources that are wastes of production and consumption. The volume of industrial wastes increases higher rates, than public production, and has a tendency to the passing ahead height. Only on moving away of them and warehousing expended on the average 8-10% of basic producible products.

Utilization of industrial wastes provides a production the rich source of cheap and often already prepared raw material; results in the economy of the capital investments, intended for building of enterprises, obtaining and processing raw material, and increase of level of their profitability; to freeing of зна чительных areas of the landed lands and decline of degree contamination of environment. An increase of level of utilization of industrial wastes is the major task of state value.

1. Actuality of theme

General mass of accumulated industrial wastes makes an about 30 milliard of  Dumps, waste banks,  is placed on an area 160-180 thousands ha, that increases at a speed of 3-6 thousand ha/year [2].

Processing of slag and utilization of metallurgical slags got wide distribution in the world. On modern metallurgical plants not only all formative slags are utilized but also old slag dumps are gradually developed. In slag dumps on the plants of our country hundreds of millions of tons of slag are yet kept, dumps occupy considerable areas.

2. Processing of wastes

By main factors, qualificatory possibility ecologically to safe utilization of wastes, their bodily condition and chemical composition become again. On it economic feasibilities of existent technologies are laid on and economic expedient difference taking into account ecological one prospects. It is possible to distinguish three going near utilization of wastes: direct use, processing with extraction of useful components, elimination. The first are most rational to cement industry. Basic application two, but not all wastes it is possible to process. In spite of presence of useful components, on a present stage there can be not effective technologies of their extraction. Such wastes cheaper and safer to destroy. We will consider directions utilizations of wastes are in ferrous metallurgy that becomes them by a consumer [1].

2.1 Direct utilization of wastes

Direct use – most simple and effective way of utilization of wastes, supposing minimum expenses on their processing. It is possible and rationally, if wastes are ecologically safe and does not contain extractive components. Or, vice versa, the useful prevails in them component, as in скрапе. Off some hand, except sorting on to composition, he is used for smelting of steel. Utilize like wastes of engineer, army technique and any scrap-metal, id est process unown wastes of metallurgy. By other example direct use there is a dross (addition at smelting of steel, production of agglomerate)

Picture 2.1 – A slag dump is in Ukraine [8].

Typical example of wastes first type domain slag (рiс. 2.2).

Picture 2.2 – Domain slag

He does not contain extractive components and ecologically safe. His exit makes more than 150 million т in a year. However existent technologies of processing allow to assert that domain slag – it is not departure, and industrial raw material that in industrially developed countries used practically fully. Application of slag at the production of cement gives additional ecological effect, because reducespower expenses on 40 diminishes extrass CO2.

2.2 Processing of wastes with extraction of useful components

With extraction of useful components different wastes can undergo processing, but their composition, dispersion, humidity is hampered application of existent technologies. We will consider wastes that constantly accumulate and require new areas for storage. It is milltailingss, to the dust and  slags of the coloured metallurgy. The concentration of iron in these slags arrives at 25% and more, and in dust and slags of ferrous metallurgy to 60% exceeds the indexes of raw ores. But all of them contain the admixtures of volatile metals, foremost Zn(3-7 slags of copper plants 6-10 leaden). There are Cu in the dumps of the coloured metallurgy, Co, Ni, Ag. The enormous supplies of wastes resulted in the origin of original technogenic deposits

Romelt (pic. 2.3) is a new method of processing of wastes. A process of Romelt is the continuous method of receipt of cast-iron from iron-bearing raw material and wastes with the use of unscarce and cheap brands of unclose-burning coals. In a stove with fusion of slag through lower oxygen-air mixture that mixes a slag intensively is blown. Stove футерована only to the level of overhead. Other part is executed from the water-cooled elements – caissons. On the cold surface of caissons a slag forms a hard crust. So the problem of firmness of lining-up decides in touch with slag fusion. A charge is ore or iron-bearing wastes(dross) and coal – continuously loaded from above on the surface of slag fusion with a temperature 1400-1500°С of pre-treatment of pulverulent raw material or coal is not required. Coal performs the two duties. His burning together with the reheat of gases supports a temperature in a stove. In addition, he provides renewal of oxides of iron and forming of cast-iron that as drops is besieged on the bottom of stove. A metal and slag are produced through opening executed on different levels [9].

1 – a bubbling zone of slag, 2 – a slag store, 3 – metallic bath, 4  – steel-lined bottom, 5  – slag and metallic crossflows, 6  – the loading opening, 7  – a top of stove, 8  – a bottom, 9 – overhead, 10 – a zone of quiet slag, 11  – the water-cooled panels

Picture 2.3 – Chart of stove Romelt

2.3 Elimination of toxic wastes in metallurgical aggregates

Some wastes of chemical industry, exhaust or forbidden to to the use materials of medicine, means of chemical defence, electrical engineering liquids have high toxicness. For their eliminations are usually offered new technological processes and aggregates, that it is constrained with heavy tolls. In addition, elimination not must result in formation of secondary foods, sometimes yet more toxic [6].

3. Experimental processing of data

Experimental part of work consists in carrying out tests on laboratory setting(рiс.3.1) above by working standards – domain and martin slag. In a process carrying out tests was conducted growing of materials shallow with subsequent by extraction of metallic components.

1 – an electric motor, 2 – a reducing gear, 3 – the revolved cage, 4 – a drum

Picture 3.1 – Chart of the laboratory setting

For growing of wastes shallow it is necessary preliminary to dry out material. It is whereupon necessary to produce the throughs of material, in future to estimate efficiency influences of process of growing shallow on extraction of material. For we conduct a few experiments are with different duration (рiс 3.2).

Picture 3.2 – Chart of dependence of degree of growing shallow from time

Extractions of metal we produce by means of magnets and estimate maintenance of metal in a slag (рiс. 3.3).

Picture 3.3 – Chart of dependence of the extracted metal from a degree grade 

Influence of process of growing shallow on extractions an exposure consists shallow particles of metal from the large pieces of metallurgical slag.

4. Increase of efficiency of growing shallow

On durability of solids at their destruction some liquids have influence chemically or physically occlusioned on an outward surface and surface of internal perigastriums. Under influence of physisorption of active substances there is lowering of his durability on the surfaces of solid. This phenomenon is named an adsorption effect or effect of Rebindera. He has influence on the process of growing shallow. The mechanism of lowering of durability appears following.

During deformation of solid under influence of external forces микротрещины that can close(healed) up after the removal of loading appear in a superficial layer. The adsorbed substance, migrating on a surface, flows in cracks, arrives at their mouth and renders a splitter effect on the walls of crack or prevents to their closing.

Three types of influence of environment in that there is growing shallow are experimentally set. All depends on the size of decline of superficial energy of solid. There is strengthening of plastic properties of solid at an insignificant decline. At a decline fragility of body increases in several times, and the spontaneous dispergating can come at a yet greater decline.

On the display of adsorption effect large influence is rendered by the defects of structure of solid. There is surplus of free energy in the places of defects, there is intensive co-operation of molecules of liquid and hard there. Features physical and chemical co-operation between an environment and surface of solid substantially influence on an adsorption effect. The mechanical terms of growing shallow also influence on the size of effect.

As be obvious from the stated, an adsorption effect is very specific and shows up differently depending on physical and chemical properties of solid and liquid and terms of growing shallow. The noticeable action of superficial active substances (SAS) is experimentally set at the dry growing shallow. Small additions of water improve growing of wastes shallow.

In practice of the dry growing shallow in rattlejacks there is sticking of powder on the surfaces of grinding a tel. efficiency of growing shallow goes down Here. This phenomenon differs from aggregating, the stratified sticking is explained by formation of capillary-coagulative structures in that particles are bound by the layers of liquid. At growing of absolutely dry powders shallow and at the wet growing of sticking of material shallow on grinding bodies not observed [7].

Conclusions

The sharpness of problem, in spite of sufficient amount of ways of decision, is determined by the increase of level of education and accumulation of industrial wastes. Foreign countries directed effort, foremost, on warning and minimization of formation of wastes, and then on  secondary use and development of effective methods of the final processing, rendering and final moving away harmless, and burial places only of wastes not contaminating an environment. All these measures, indisputably, diminish the level of negative influence of wastes of industry on nature, but does not decide the problem of making progress their accumulation in an environment and, consequently, to the increasing danger of penetration in the biosphere of harmful substances under influence of technogenic and natural processes. The variety of products that at modern development of science and technique can be zero-emission got and consumed very limits, attainable only on the row of technological chains and only by highly remunerative industries and production amalgamations.

Note

This master's work, namely its computational part, is not completed yet. Final completion: December 2012. The full text of the work and materials on the topic can be obtained from the author or his head after this date.

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