IM 2017 August 17 | Page 16

OPERATION FOCUS This mining technique prevents dangerous deformations of the underworked rock mass and consequently eliminates the penetration of underground water into the mined-out area. Variations include mining with yielding pillars, mining with support pillars, and a combination of both. JSC Belaruskali is also the only major potash mining company today which uses the pillar mining technique and longwall shearers. The pillar mining of the 2nd and 3rd potash seams by longwall mining (face mining) with roof collapse has been used since 1969. The following types of pillar mining are used: I Complete mining of the 2nd seam and the layers II, II-III and III of the 3rd seam without longwall slicing I Selective mining of the layers II, II-III and III of the 3rd seam without longwall slicing I Layer mining of the 2nd seam I Layer mining of the 3rd seam. At the present time about 70% of ore is mined using longwall mining techniques with a fleet of Eickhoff shearers (faces 180-300 m long). The 3rd potash level has three productive sylvinite layers (II, III and IV) divided by seams of halite. When using the combined system of mining, the upper (IV) sylvinite layer is mined using the pillar technique and the subsequent layers (II and III) are mined by the chamber method of mining. This system is now seldom used due to a big loss of the mineral recovery from the layers II and III. Lastly, the development workings within the deposit are driven by continuous mining complexes, which consist of a continuous miner, a conveyor hopper and a shuttle car. The workings are 3.0, 4.0, 4.05, and 4.5 m wide (depending on the type of continuous miner used and the purpose of the workings). The height is 2.4, 2.6, or 3.0 m and the floor of the working can be undercut if necessary. When sylvinite and halite are extracted separately using the layer mining method the content of potassium chloride (KCl) in the mined ore rises up to 30-35% because in this case only sylvinite layers are extracted, while halite is left underground. Every year more than 1 Mt of waste rock is stockpiled in the worked-out areas underground, thus reducing the environmental impact on the industrial district and preventing deformations of the land surface. JSC Belaruskali also now has the rights to use the subsurface resources within the western part of the Nezhinsky plot of the Starobin deposit. The company additionally has the possibility to mine the ore reserves of the Darasinsky plot totalling 180 Mt. The next mining phase involves opening the 4th potash level at PU 2. The reserves of the 1st potash level at PUs 3 and 4 are also included in 14 International Mining | AUGUST 2017 plans for future mining. The improvement of mining and processing techniques also allows JSC Belaruskali to consider reserves located at a depth of 1,000 m or more as the source of replenishment of ore resources. Production and exports, new horizons Total processed KCl fertiliser production from the whole mining complex stood at about 9.5 Mt in 2016, though this was lower than usual due to delays in Chinese contracts and a low demand globally. However, the company still maintained a higher output than the other potash majors. Belaruskali ships potash to southeast Asia, Europe, Africa, Brazil and North and South America. There are also so-called contract markets, such as China and India. Overall the group exports to more than 90 countries. Most of the potash is railed to Klaipeda, a dedicated potash port in Lithuania. The company is also developing a completely new mine and plant about 150 km away known as Petrikov, where the first phase of the factory will be commissioned in December 2019 and where the designed capacity will be reached in December 2021. The plant’s output capacity will be at least 1.5 Mt of KCl per