Bakal mining administration

BAKAL MINING ADMINISTRATION (RU: Бакальское рудоуправление) is one of the oldest enterprises for the extraction, beneficiation, and agglomeration of the iron ores within the Bakal group of the deposits (more than 20), within the Satka district of the Chelyabinsk province of the Russian Federation. It has been created on the base of the Bakal deposit of the iron ores, which has been discovered during the 1757. It belongs to the "Uralruda" consortium of the All-Union "Soyuzruda" consortium of the Ministry of the ferrous metallurgy of the USSR. The major industrial centre is the Bakal city. It includes the 7 open pit mines (one of them is quartzitic), underground mine, 3 crushing-screening plants, drying and baking-beneficiation plants, railway, automobile transport, and other workshops.The cross section of the Bakal ore field

The group of the deposits (Shikhanskoe, Petlinskoe, Irkuskanskoe, Bulandikhinskoe, named after OGPU, and others, the area is 150 square kilometres) is situated within the north-eastern part of the Bashkir anticlinorium on the limbs of the Bakal syncline. The ore field (Figure # 1) is formed by the sedimentary-metamorphic rocks of the Upper Proterozoic.

The mineralization localizes itself within the carbonatic rocks of the Bakal stratigraphic suite (formation), and represents by itself the group of the isolated ore bodies with the tabular, nest-shaped, and lenticular shapes. The ore bodies are represented by the depositions of siderites and limonites. The thickness is 4-120 metres, the length is up to 3.5 kilometres. The strike is near-meridional, the angle of the dip is up to 85 degrees to the north-west and south-east. The reserves of the iron ores are 620 million tonnes (1981) with the content of Fe of 29%-46%. The major ore minerals are the magnetite, which is containing siderite (sideroplesite), and within the zones of oxidation, hydrogoethite, hydrohematite, goethite. The accompanying minerals are: the ankerite, calcite, magnesite, dolomite, and quartz. The latter mineral forms the industrial depositions of quartzites.

The general view of the open pit mine

The mining-technical conditions of the development are favourable. The deposit is developed to the depth of 150-300 metres by the open pit method, and deeper by the underground method. During the underground works, the unsealing of the depositions has been performed by the five shafts: two auxiliary, two for ventilation, and one inclined, which is equipped with the conveyor with the length of 920 metres. The system of the development is the sub-level with collapse (the height is 12-15 metres) with the discharge at the end. The delivery of the ore is performed by the self-propelled machines, scraper winches, electrical locomotives; the issuance onto the surface is performed by the inclined conveyor (the width of the belt is 1400 millimetres). Since the 1979, there is used the chamber system of the development with the delivery of the ore by the scraper winches. The height of the chambers is 20-30 metres. The unsealing of the open pit mine fields is performed by the internal grouped helical and single semi-trenches. The height of the working bench for the ore is 10 metres, for the overburden rocks is up to 20 metres. The loading is performed by the excavators with the bucket with the capacity of 4.6 and 8 cubic metres. The transport is combined: by automobiles within the bottom zones of the open pit mines, with the usage of the dump trucks with the load capacity of 27 and 40 tonnes, on the top horizons and dumps of the waste rocks by the railway, the electrical locomotives with the load capacity of the dump cars of 105 tonnes. The extraction of the iron ores is 4.4 million tonnes (1980), including 3.5 million tonnes of siderites; there is extracted in small quantities also quartzite for the production of ferrosilicon. The extraction of the ore is 81%. At the beneficiation plant, the ore is subjected to the magnetic beneficiation and agglomeration, the content of Fe is 48.5% within the concentrate, and is 42% within the agglomerate.