Master's portal

DonNTU

Papuna Natalya

Theme of master's work:

"Waste heaps processing by agglomeration method"

E-mail: Natalya_Papuna@mail.ru

Abstrakt of master's work

Importence of the theme

A problem of ecological deformation of territories under influence of the anthropogenous factor is importent in the modern world. Intervention in natural processes leads to environmental contamination. The important environmental problem for Donetsk area is influence of processes of coal output.

Waste heaps render negative influence on an atmosphere, soils, superficial and underground water sources.

In damp air sulphurous anhydride which is allocated from waste heaps, forms a sulfuric acid which together with rains drops out on the ground. When the metal dust even more is introduced poisonous salts of a sulfuric acid are formed gets.

Many of waste heaps burn, and it promotes significant change of structure of atmosphere air and gets of acid rains to an atmosphere 4-5 t carbon oxyde and from 600 up to 1100 kg of sulphurous anhydride, and also small amounts of hydrogen sulphide, оксидов nitrogen and other products of burning are allocated from one burning heap per a day.

Underground waters at interaction with waste heaps are strongly enriched weighed particles, from alkalescent become sour (рН reaches 2-3 and it occurs at 15 % of mines), from fresh and saltish with a mineralization from 0,2 up to 3 g/l turn in salty with a mineralization 5-30 g/l and very rigid.

It is established, that on a share of the coal industry it is necessary 55-70 % of all substances polluting reservoirs of region. Significant pollution is given with waste heaps.

On the grounds borrowed under waste heaps of soil, unlike natural, in the top horizons are broken (are poured, are cut off, are mixed). In such soils the acid-alkaline balance and physicomechanical properties are changed. In the sealed territories, in waste heaps mine breeds disappear eventually under action of ability to live of bacteria in a combination to action of a moisture and fluctuations of temperature. This process negatively affects adjoining territory. Waste heaps pollute adjoining black earth soil and make them unsuitable for all alive.

The conic form of heaps and a greater steepness of their slopes (up to 45o) promotes catastrophic erosive processes. It is annually 1 hectares of a surface of waste heaps 86 up to 900 m of breed washed from.

Washed off breed is very toxic, as pyryte oxidation promotes that neutral breed of waste heaps eventually becomes sulphur acid with рН 3. The sulfuric acid formed as a result of pyryte oxidation, dissolves various metals, and they migrate to adjoining territories.

Waste heaps can be defined as the objects bringing significant harm adjoining soils. Pyrytized coals are rich with uranium. In coals it basically is presented by nasturanium (uranium oxyde). Formed as a result of pyryte oxidation of heaped weights the sulfuric acid dissolves all metals, including uranium. Dissolution of uranium leads to increase of a radio-activity of breed of waste heaps [1].

Hence, the problem of processing of waste heaps is actual.

The purposes and problems

- Studying of world experience under the decision of a problem of waste heaps recycling;

- Development of the universal scheme of processing of waste heaps by a method of agglomeration;

- Reduction of harmful influence of waste heaps by an environment by their processing by a method of agglomeration;

- Introduction of the given project.

Planned praktical result

Waste of extraction of natural resources and the rests of the raw material which has been not used during manufacturing of basic production, not always completely lose the economic importance and frequently too can be used as raw material for manufacture of this or that production. Heaped breed of collieries concerns to such waste. Now such ways of its recycling, as reception of building materials and coal ferilizers, manufacture of bauxites and aluminium alloys, branch of magnetic ferriferous connections from waste heaps, allocation Germanium from waste heaps, allocation rare ground elements from waste heaps are known.

The scheme of processing of waste heaps by method of agglomeration (figure 1) is offered by us.

Figure 1 – The technological scheme of reception producing agglomerated pyryte made from coal output heap.

Waste of coal output subject to crushing up to fraction of 0-3 mm and to averaging. Then they are humidified with water and mix up in drum-type amalgamator for charge reception prepared to sintering. After that agglomeration process becomes – the charge is exposed to sintering at conveyor type agglomeration sinter. The carbon containing in breed, is a fuel for sintering materials. The ready product of sintering represents agglomerated "pie" – agglomerated pyryte. Depending on further using it can be exposed to various kinds of crushing.

Agglomeratred pyryte can be used in: construction of dams and platinums; manufacture of cement; manufacture of slag brick and a brick; construction automobile ways and railways; manufacture of ferro-concrete products; manufacture of concrete; monolithic housing construction.

The review of the basik questions

The basic questions arising at prevention of negative influence on an environment by processing waste heaps are:

- Reduction of influence on components of a surrounding environment;

- Reduction of accumulation of waste and clearing of the grounds;

- Reception of economic benefit due to economy at payments for accommodation of waste, due to the released territory, etc.;

- Decrease in consumption of natural resources.

In territory of Donbass there are more than 1.5 thousand waste heaps, on the average 1144 м³ breeds is totaled in each of them. Waste heaps are scattered on all territory of Donbass on the area of 800 hectares. They borrow significant territories and render negative influence on an atmosphere, ground, superficial and underground water sources. Therefore the problem of recycling of waste heaps at the moment is actual.

Processing of waste heaps by a method of agglomeration allows to solve questions in a greater degree.

The list of the basik results

A result of work is the scheme of waste heaps processing with the help of agglomeration, which allows to receive ecological, economic and social benefit.

Ecological benefit is decrising negative influence on an environment decreases.

Economic – decrease in payments for damage that caused by waste heaps application of the released territory in industrial needs receiving agglomerated pyryte.

Social ben is creation of workplaces on technological service at the agglomerated manufacture enterprise.

Conclusions and prospekts of reseach

At introduction of the given technology inevitable emissions of a dust, sulphurous anhydride, nitrogen dioxyde, carbon oxyde are assumed to atmosphere. Installation of multistage system of gas cleaning, which will provide full gas clearing from polluting substances is necessary for prevention of their hit to atmosphere.

At the projected enterprise the organization of turnaround system of water supply. This system excludes dump of the polluted sewage in water objects.

Fine agglomerated pyryte are The firm emissions at the agglomerated pyryte manufacture particles, they are completely utilized in the given manufacture.

So given technology allows to solve an environmental problem, and also to receive an economic ben not only due to received agglomerated pyryte sintering, which can be used in a building industry, but also due to the grounds clearing and decreasing in charges for damage payment put to environment.

1. Васильева И. Териконы поджигают невидимки. http://www.geonews.com.ua/index.cgi?a=7502

2. Красавин А.П. Защита окружающей среды в угольной промышленности М.: Недра, 1991. – 219 с.

3. Жизнь растений / Под редакцией А.А.Федорова. – М: Просвещение, 1974. – Т.1. – 528 с.

4. Метод использования энергии горящих терриконов. http://www.necin.kiev.ua/rus/publications/terikon.htm.