RU2038476C1 - Coal deposit exploitation method - Google Patents

Abstract

FIELD: mining industry, in particular, process for exploitation of steep fire-hazardous coal beds. SUBSTANCE: method involves working of lower floor and stowing goaf in upper part of floor; working lower part of floor by means of systems of artificial caving of roof. Inclined roof of bed portion which is worked simultaneously with stowing, is not below height of natural balance doming. Artificial caving of roof is effectuated by undercutting its lower border of portion of floor worked with stowing. Length of blast hole for roof caving is determined from expression recited in Specifications. EFFECT: efficient exploitation of coal deposit. 2 cl, 3 dwg

Description

 The invention relates to the mining industry and is intended for mining steep and inclined coal seams under the fired areas.

There is a method of developing powerful coal seams, prone to spontaneous combustion in areas under extinguished endogenous fires, as well as in locks of anticlinal and synclinal warehouses with full laying of the worked out space [1]
The disadvantages of this technology are lower labor productivity and higher cost (2-3 times) compared to development systems with a complete collapse of the roof.

There is also known a method of underground mining, including mining the excavation sections, mining the minerals in the overlying mining section with collapsing overlying rocks, mining the minerals under the mining and collapsing mining section systems with the laying of the worked out space with hardening mixtures, mining the minerals under the laid-out worked out space collapse of overlying rocks and the formation of arches of natural equilibrium over the worked out space [2]
The aim of the invention is to provide a controlled collapse of the roof rocks during the extraction of minerals in the sections of the reservoir, worked out under the sections worked out with the tab, and by selecting the optimal (rational) parameters of these sections increase the efficiency of mining.

где h_o наклонная высота выемочного участка, отрабатываемого с обрушением кровли под заложенным выработанным пространством, м;
h₃ наклонная высота выемочного участка, отрабатываемого с закладкой, м;
К_р -коэффициент разрыхления пород кровли.The goal is achieved by the fact that during the development of coal deposits, including development of the seam by mining sites, mining of coal in the overlying mining site with collapse of overlying rocks, mining of coal under the mining excavated site with collapse of the mined-out systems, mining of coal under the laid-out mined-out area with collapse of overlying rocks and the formation of arches of natural equilibrium over the worked out space, the inclined height of the excavation section worked out with the bookmark, ayut least arch height natural equilibrium overlying rocks and collapse overlying rocks in the recessed portion is performed by laying them forcibly trimming blastholes which bupyat excavation at the lower end portion of waste with a bookmark. The length of the blast holes is determined from the expression
l _ck Km, where m is the reservoir thickness, and the coefficient K is determined from the expression
K =

where h _{o the} inclined height of the excavation section, worked out with the collapse of the roof under the laid-out mined space, m;
h _{3 the} inclined height of the excavation section, worked out with the tab, m;
To _{p is the} coefficient of loosening of the roof rocks.

 Figure 1 shows a diagram of the development of part of a coal field represented by a steep seam, a section in the plane of the seam; figure 2 is a vertical projection of the excavation section of the reservoir; figure 3 design scheme.

 The mineral deposit, represented by a retinue of steep and inclined coal seams, is mined by mining sites, while on the upper floors (horizons) 1 coal mining is carried out with the collapse of the overlying roofing rocks. The underlying stages are worked out according to the combined technology: the upper part of the floor is worked out with the laying of the worked out space, including the use of hardening mixtures, and the lower one with the collapse of the roof.

The excavation section of the reservoir is opened with a cross-turn 2 on the withdrawal horizon and a ventilation cross-section 3. From the cross-section 2, the main (drawback) drift passes through the formation 4. Having determined the inclined height of the sub-floor h ₃ , which must be worked out with the tab, pass under-floor drift 5, at the level of which the first horizontal or transverse-inclined layer 6. The overlying part of the formation to the horizontal horizon is worked out by layers 7 with the laying of the worked out space. The inclined height h _{3 of} this sub-floor, worked out with the tab, take at least the height of the arch of the natural equilibrium of the overlying rocks.

 After the upper part of the formation is completely worked out with a tab at the boundary of the excavation section, the treatment works begin in the lower part of the formation, which, for example, is worked out by pillars in fall 8 using shield ceilings or in some other way. At the same time, before the start of treatment work in the lower part of the floor with the collapse of the overlying roof rocks at the level of the first worked out layer 6, i.e. at the lower boundary of the excavation section (sub-floor) worked out with laying, forced collapse of the overlying roofing rocks is performed by cutting them with blast holes 9.

The length of blast holes 9 is determined from the expression l _ck Km, where m is the thickness of the reservoir, m; K coefficient, determined from the equality of 0.5 x h _o x K (K _p -1) = h _o h ₃ , where h _{o the} inclined height of the sub-floor of the excavation section, worked out with the collapse of the roof, m; h _{3 the} inclined height of the sub-floor worked out with the bookmark, m; To _{p the} coefficient of loosening of the rocks of the roof.

The coefficient K is determined and optimized based on the calculation scheme (Fig. 3), which is based on the fact that the volume of the worked-out space with roof collapse V _o is equal to the sum of the volumes of the bypassed filling array V ₃ and the increment of the volume of destroyed roofing rocks V _k due to their loosening V _cr V _to ˙K _p , i.e., V _o V ₃ + (V _cr V _k ), and V _o h _o ˙ m˙l ₃ , where l _{3 is the} length of the face along the strike of the formation.

The volume of the worked out space filled with the bookmark, V ₃ h ₃ ˙m˙l ₃ . It is accepted that at least half of the volume of roofing cut by blasting over the worked out space of the lower part of the fire section collapses, i.e. V _to 0.5h _o ˙l _cк ˙l ₃ .

 Transforming the above expressions, we obtain a formula for determining the coefficient K in the expression for determining the necessary (optimal) length of blast holes.

 Application of the proposed technology will allow more efficient mining of excavated sections of powerful steep formations located under decommissioned (extinct) endogenous fires.

Claims (2)

 1. METHOD FOR THE DEVELOPMENT OF COAL DEPOSITS, including mining of a seam by mining sites, mining of coal in an overlying mining site with collapse of overburden, mining of coal under mining with collapse of a mining site with laying of mined-out space, mining of coal under paved mined-out space with collapse of light arches of natural equilibrium over the worked out space, characterized in that the inclined height of the excavation section worked out with the bookmark is mayutsya least arch height natural equilibrium overlying rocks and collapse overlying rocks in the recessed portion is performed by forced laying their trimming blast hole, which is drilled at the lower end portion of the excavation, with laying waste. 2. The method according to claim 1, characterized in that the length l _{s to} blast holes is determined from the expression
l _{s to} K m
where m is the thickness of the reservoir, m;

where h _{o the} inclined height of the excavation section, worked out with the collapse of the roof under the laid-out mined space, m;
h _{c the} inclined height of the excavation section, worked out with the tab, m;
K _{p the} coefficient of loosening of the roof rocks.

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