Borehole Hydraulic Mining

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Borehole Hydraulic Mining


a technique used in underground extraction of a solid mineral, in which a solid mineral is broken up and delivered to boreholes by water and removed to the surface as a hydraulic mixture. Borehole hydraulic mining is used primarily to extract loose and weakly cemented ores, such as phosphorite deposits that occur in layers relatively close to the surface.

Borehole hydraulic mining involves drilling wells ranging from 100 to 300 mm in diameter. The ore body is broken by the hydraulic pressure gradient in the case of very loose and greatly flooded ores and by a stream of water otherwise. In the first instance, the water in the layer is pressurized in one group of wells and the pulp is pumped out of neighboring wells; in the second, water under pressure is fed into the nozzles of a monitor.

The destructive action can be intensified by means of vibrations or explosive charges; alternatively, the ore body can be weakened at the start of mining operations by chemical or microbiological methods. The hydraulic mixture is brought to the surface by a hydraulic elevator, an air lift, or an air lift combined with a hydraulic elevator; it can also be brought to the surface through the creation of excess pressure in the layer.

Borehole hydraulic mining makes it possible to work deposits occurring under bodies of water. It ensures a smooth flow of operations and allows automated processes to be used.


Besshakhtnaia dobycha gornokhimicheskogo syr’ia. Moscow, 1969.
Problemy geotekhnologii. Moscow, 1972.


The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
For example, researchers from Jilin University, China, have demonstrated the suitability of the borehole hydraulic mining method for extraction of deep-deposited oil shale [3, 4].
Borehole hydraulic mining is an emerging technology that differs from traditional underground tunnel mining and open-cast mining.
Identifying a reasonable drilling spatial arrangement and maximum exploitation radius currently remains a problem to be solved in the borehole hydraulic mining of oil shale.
The mining area layout is shown in Figure 2, in which circles denote the cylindrical excavations formed by borehole hydraulic mining, and A is the drilling interval.
1) The FLAC3D, developed according to the principle of three-dimensional fast Lagrangian analysis, demonstrated its ability to reasonably simulate the yield or plastic flow characteristics of rock mass in the actual process of production in the Nong'an oil shale borehole hydraulic mining area.
3) This study applied the three-dimensional fast Lagrangian method to the oil shale borehole hydraulic mining project design, and the research results provided a reference basis for shale borehole hydraulic mining.
So, all the factors affect borehole hydraulic mining. Even more, compressive strength of the rock is comprised of many factors, including mineral composition, grain size, bulk density, porosity, etc [4].
So, the purpose of this experiment was to obtain empirical physical and mechanical parameters of Nong'an oil shale in both horizontal bedding orientation and vertical bedding direction which could serve to determine technological parameters of borehole hydraulic mining for oil shale.
The results build up the foundation for borehole hydraulic mining. Weathering coefficient was in the range of 0.40 < [K.sub.f] < 0.80.
The values of compressive strength of oil shale in the vertical bedding direction and horizontal bedding orientation were only 10.9 MPa and 17.4 MPa, both less than the value of compressive strength limiting borehole hydraulic mining. So, it is possible to exploit hydraulic mining of oil shale based on the current technology and equipment.
According to the calculation formula of hydraulic pressure of oil engineering work and the analysis of the expediency of using borehole hydraulic mining for exploiting target rocks with different physical and mechanical properties, as well as the analysis of quantitative indicators, the values of coefficient [K.sub.o] (the value of critical pressure at hydraulic breaking of rock/compressive strength of rock) of hydraulic jet erosion calculated for different rocks are gained, which are 0.1172-0.1228 for mudstone, 0.1249-0.1269 for sandstone, 0.1197-0.1229 for limestone, and 0.1219-0.122 for granite.
Borehole hydraulic mining is to be conducted from the bottom upwards.