外文翻译-使用矿物煤的吸附作用进行矿井污水处理.docx

1、英文原文Use of Mineral Coal for Sorption Sewage TreatmentTreatment of mining, industrial, household and other sewage is an actual problem for many mining and processing enterprises. Coal-mining industry is not an exception. Usually, at coal enterprises, treatment of mine sewage before it is dumped consi

2、sts in settling and subsequent filtering. Many pollutants are not removed from the sewage by this method. Hence, dumped water frequently does not satisfy sanitary requirements regarding the permissible content of oil products, dissolved substances and other parameters. For additional cleaning of sew

3、age it is possible to use sorption methods. By these methods water is cleaned of oil products, heavy metals, a number of organic substances and other polluting substances, depending on the used sorbent properties. Both natural and artificial materials can be used as sorbents. Constraint for wide use

4、 of sorption methods of sewage treatment in the coal industry is high cost of the majority of sorbents. A number of technologies for obtaining inexpensive and good quality sorbents from coal minerals have been developed. These sorbents can be manufactured directly in coal mines which has additional

5、advantage of reducing transport costs. The processes sorbents may be recycled or burnt. Apart from that production and sale of sorbents can serve the coal-mining enterprises as an additional source of income. One of the most widespread sorbents is activated coal. Quality activated coals are carbon s

6、orbents, having an internal specific surface of more than 500/g, and characterized by iodine adsorption (iodine value) of more than500mg/g. mineral coal, peat and wood can serve as raw materials for activated coal production. Traditional production techniques of activated coal include two basic stag

7、es of thermal processing of the initial carbon-containing raw material-carbonization and activation, done in different devices. Both stages are energy-consuming and ecologically dangerous, which explains the high cost of activated coal, received through this technology (1200-4000 dollars/MT). Carbon

8、ization is the elimination of volatile substances by heating up to the temperature of 600-900, because with volatile components there are basically formed the oxygen and hydrogen, and increase carbon content in initial raw material. Carbonization is done in mining or rotating furnaces with utilizati

9、on of external form-holder, as a rule, waste gases with temperatures of 600 and higher. Activation means increasing the volume and pore surfaces of carbonized material at heterogeneous reaction. The most used reagent is water vapour with the temperature of 900 and higher, and the process takes 15-20

10、 hours. Both stages are energy consuming and pose threat to environment. For one tonne of activated coal from 2 up to 4 tonnes of specific fuel like crude oil and natural gas are consumed. From 1000 up to 1500 m of processed gasses with high content of SOx (1-2 g/ m), H2S (200-250mg/ m), resinous su

11、bstances (10-40mg/ m), phenols (50-70mg/ m), carbon oxides (up to 5%) and also other substances which are carcinogenic and mutagenic are formed and released into the atmosphere during both stages. High-energy consumption and environmental danger, which requires large investments in nature protection

12、 activities, result in the high cost of quality-activated coal. Another group of carbon sorbents, which was widespread in the 80s, consists of inexpensive carbon sorbents used in nature protection technologies and industry. Such sorbents are produced by a one-phase technology, without additional act

13、ivation. Their adsorption activity is not high (iodine value less than 300mg/g) but the cost is low (250-700 USD/MT).because the price of these sorbents is comparable to the cost of their regeneration, they are used only once and are burnt after saturation. The leaders in the production of such sorb

14、ents are Rheinbraun AG (Germany, 200 thousand MT per year) and Australian Char Ltd (Australia, 150 thousand MT per year), which produce brown coal semi-coke used for treatment of wastewater and smoke. In Russia research work in this direction is conducted, but only test works have been done so far,

15、although the quality of carbon sorbents obtained from Kansk-Achinsk coals did not concede to production from Rheinbraun AG and Australian Char. One of the directions of utilization of semi-coke from Kansk-Achinsk coals, production of which was planed at Krasnoyarsc thermal power station 2 (device ET

16、X-175), was its utilization as carbon sorbent. The reason for production of inexpensive carbon sorbents by one-phase technologies being not developed in Russia is the absence of demand for this product. This production is basically used for cleaning of sewage, however there is no effective ecological service in Russia, and the penal sanctions of the environmental protection legislation are so insignificant that industrial enterprises do not have ant motiv