Ensuring dust and explosion safety during underground coal mining is one of the most important tasks of industrial safety and labor protection departments. The main method of preventing explosions of coal dust settled in mine workings is to process them with stone dust (rock dusting). The traditional methods of quality control of rock dusting include radioisotope, optical and chemical methods. To implement them, the devices are equipped with environmentally harmful radioactive elements, expensive optical sensors, desiccants and replaceable flasks with chemical reagents, which increases the cost of analysis and its duration. The measurement error of these devices is 10 % or more. The main purpose of the study is to develop and substantiate a new method for monitoring the dust and explosion safety of mine workings, which will be devoid of the disadvantages of the methods mentioned above. It is proposed to evaluate the quality of rock-dust distribution by a fundamentally new way – thermogravimetric. The method was tested on the dust of coal mines in Kuzbass and the Vorkuta basin, including dust samples taken in mines with actual explosions. The article presents the results of experimental studies of the processes of thermal destruction of coal and stone dust mixtures. The non-overlapping intervals of the thermogravimetric reaction are identified: moisture yield (35-132 °С); volatile matter yield from coal (380-580 °С); thermal degradation of limestone with carbon dioxide yield (650-850 °С). Methods and mathematical dependencies for processing significant and qualitative identification characteristics of thermogravimetric curves in determining the content of non-combustible components in a sample of mine dust are considered.
The tailings dumps of the ironore mining-reprocessing enterprises exert extremely negative influence on the environment, but at the same time, under the conditions of the impoverishment of iron ores they are potential raw source. In connection with this, a question of involvement in processing of the tails containing iron is extremely urgent. In the article the technology on processing of the waste of the beneficiation of iron ores is suggest. In this case the clotting of the obtained concentrates can be carry out by briquetting. In the work are also given the results of researches of the iron-containing tails concentrating and briquettability of the concentrates obtained of them.
Briquetting in ferrous metallurgy is the earliest way clotting. In the beginning of XX century briquetting has been forced out by agglomeration basically for the reason considerably more productivity of process of agglomeration. The alternative agglomeration became pelletizing which share from the XX-th century middle steadily grows that is quite explainable essential increase in manufacture fine particle concentrates. However briquetting has a number of advan- tages. And for separate kinds of iron ores briquetting can appear preferable process. Such ores are the rich iron ores containing 60 and more % iron in ore. The technology of briquetting includes, preliminary screening for removing of large classes; dispensing and preliminary mixing 85-90 % martite, iron-micaceousmartite ores and 10-15 % hydrohematite ores; mixing with connective substances; pressing; drying. The received briquettes have density 3200-3500 kg/m3, durability on compression about 4,5 MPа.
Iron ores is one of the main types of minerals used used by mankind. Practically all domestic deposits contain 20-40 % iron ore and so are the deep concentration. Deposits of rich iron ores, containing more than 55-60 % in our country is not enough. One of these fields is Yakovlevskoye iron ore deposit. The use of dry magnetic separation of ore for the preliminary concentration did not give positive results. The study of grain-size composition of the ore showed a significant disparity in the distribution of iron by classes size that afford it possible to carry out preliminary concentration of ore screening. For ore processing flowsheet is proposed which includes crushing to a particle size of 10 mm, screening fraction of 5 mm. Larger fraction of 5 mm is used, for example, in the blast-furnace process, and the fraction smaller than 5 mm is direct to the briquetting. As binding substance for briquetting used solution of carboxymethyl cellulose, or a combination of binder based on carboxymethyl cellulose or highly active clay.
Briquetting in ferrous metallurgy is the earliest way clotting. In the beginning of XX century briquetting has been forced out by agglomeration basically for the reason considerably more productivity of process of agglomeration. As alternative to agglomeration pelletizing became. It started to be popular in the XX-th century, that is quite explainable by essential increase of manu- facture fine particle concentrates. However briquetting has a number of advantages. For some kinds of iron ores briquetting can be preferable process. Such ores are rich iron ores with iron content 60 % and more. The technology of briquetting includes crushing, preliminary screening for removing of large particle size classes; dispensing and mixing martite ore, and hydrohematite ores; mixing with binder substances; pressing; screening for removing of small size briquettes; drying. The received briquettes have density 3200-3600 kg/m3, durability on uniaxial compression more then 4,5 MPа.