RU2846586C1 - Method of open mining of mineral deposits - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: invention relates to mining industry and can be used in complex processing of minerals developed by open method. Method for open mining of mineral deposits includes detecting the irregular distribution of minerals in the subsoil, delineating the ore body, blasting of overburden rocks and movement of the blasted rock into dumps, blasting of the ore body, primary sorting of the blasted ore according to size, content and uneven distribution of the valuable component in its pieces, formation of planned ore flow from lumps with balance content of valuable component, crushing and sorting of lumps with off-balance content of valuable component at presence of signs of non-uniformity of its distribution, storage of final tailings. Prior to movement of exploded rock mass into dumps, some part of overburden rocks located in the near-contact zone with ore body is tested for presence of a valuable component. When content of valuable component exceeds 25-30 % of balance content, these rocks are supplied to reserve stock of off-grade ore. During the planned ore flow formation, pieces with the valuable component balance content are supplemented with the undersize product, extracted during the ore sizing process, and at the stage of sorting according to the uneven distribution of the valuable component in its pieces, substandard ore from the reserve warehouse is added to the rock mass. Sorting product, i.e. lumps with uneven distribution of valuable component, is loaded into crusher for grinding and crushed rock mass is separated by content of valuable component. Lumps with balance content selected in separation are directed into ore flow. Cycles of crushing and sorting of mined rock are repeated till signs of uneven distribution of valuable component in its pieces are lost.

EFFECT: increasing the completeness of extraction of minerals from the subsoil.

1 cl, 1 dwg

Description

The invention relates to the mining industry and can be used in the complex processing of minerals developed by open-pit mining.

A method of open-pit mining of mineral deposits is known, which includes outlining the ore body, blasting the overburden and moving the blasted rock mass into waste dumps, blasting the ore body, sorting the blasted ore by size and content of the valuable component in its pieces, forming a planned ore flow from pieces with a balance content of the valuable component, and storing waste tailings (patent for invention RU 2294800 C1, 10.03.2007, Bulletin No. 7, B03B 7/00).

The disadvantage of this method is the large losses of valuable components due to the uneven distribution of minerals in the subsoil.

A method for open-pit mining of mineral deposits is known, adopted as a prototype, which includes identifying the uneven distribution of minerals in the subsoil, outlining the ore body, blasting the overburden and moving the blasted rock mass to dumps, blasting the ore body, primary sorting of the blasted ore by size, content and uneven distribution of the valuable component in its pieces, forming a planned ore flow from pieces with a balance content of the valuable component, crushing and sorting pieces with an off-balance content of the valuable component in the presence of signs of uneven distribution, and storing waste tailings (patent for invention RU 2620823 C2, 30.05.2017, Bulletin No. 16, B03B 7/00; 13/06).

The main disadvantage of the prototype when used in quarries is the impossibility of involving in the development of deposits with unevenly distributed low content of minerals.

The objective of the invention is to increase the completeness of extraction of minerals from the subsoil and to expand the mineral resource base of existing and planned mining enterprises.

This is achieved by the fact that in the known method of open-pit mining of mineral deposits, including the identification of uneven distribution of minerals in the subsoil, contouring of the ore body, blasting of overburden and moving the blasted rock mass to dumps, blasting of the ore body, primary sorting of the blasted ore by size, content and uneven distribution of the valuable component in its pieces, the formation of a planned ore flow from pieces with a balance content of the valuable component, crushing and sorting of pieces with an off-balance content of the valuable component in the presence of signs of uneven distribution, stacking of waste tailings, when forming a planned ore flow, pieces with a balance content of the valuable component are supplemented with under-sieve product separated in the process of primary sorting of the ore, crushing and sorting of pieces with an off-balance content of the valuable component is carried out together with the mineralized broken off outside the contours of the ore body rock mass selected to compensate for the loss of valuable components during sorting, whereby the cycles of crushing and sorting the ore mass are repeated until signs of uneven distribution of the valuable component in its pieces are lost.

Distinctive features that ensure the solution of the task:

- supplementing the planned ore flow with under-sieve product separated during the process of primary sorting of ore by size increases the completeness of extraction of the valuable component and allows saving resources spent on sorting the ore mass, provided that there is a direct relationship between the content of the valuable component and the degree of crushing of the ore;

- crushing and sorting of pieces with off-balance content of the valuable component together with mineralized rock mass broken off outside the contours of the ore body, selected in order to compensate for the loss of the valuable component during sorting, makes it possible to involve in the development of additional volumes of poor ores and mineralized rock mass with an uneven distribution of the valuable component, not included in the contour of the reserve calculation;

- cyclic processing of ore mass with off-balance content of a valuable component, based on crushing and sorting its pieces by content and uneven distribution of the valuable component, also allows for increasing the completeness of extraction of minerals from the subsoil.

The proposed method is illustrated graphically in Fig. 1, where 1 is crushing of the ore body using explosives; 2 is crushing of overburden using explosives; 3 is an external dump for storing overburden and waste from sorting rock mass; 4 is a reserve warehouse for substandard ore; 5 is sorting of blasted ore by size; 6 is a beneficiation plant; 7 is sorting by content of valuable component; 8 is sorting by uneven distribution of valuable component; 9 is crushing in a crusher.

The method of open-pit mining of mineral deposits can be implemented as follows.

When developing a gold ore deposit with a non-uniform distribution of the mineral, cyclic preparation of the ore body and overburden rocks for extraction is carried out by crushing them using explosives 1 and 2. The parameters for conducting drilling and blasting operations during the preparation of the ore body for extraction are assigned based on the need to increase the crushing of balance ores to form a rich fine non-machine size class, provided that there is a direct relationship between the gold content in the ore and the degree of its crushing, due to the peculiarities of the geochemical genesis of the deposit.

The blasted overburden rocks are loaded and transported to an external dump 3 . Before loading, part of the overburden rocks located in the zone of contact with the ore body are tested for the presence of valuable components. If the content of the valuable component exceeds 25÷30% of the balance content, these rocks are sent to a reserve warehouse for substandard ore 4 .

When crushing ore by blasting, the gold content in the ore is redistributed - its concentration increases in small size classes and decreases in large classes. In this regard, the blasted ore is sorted by size 5 on a grate screen, and the resulting undersize product of size -300 mm is sent to the beneficiation plant 6 .

The oversize product with a size of +300 mm is sorted by the content of the valuable component 7 , for example, by the sensor separation method. Pieces with the balance content are transported to the beneficiation plant 6 , and those with the off-balance content are sent for sorting by the uneven distribution of the valuable component 8 , for example, by the X-ray absorption method. The rock mass sorted at this stage is preliminarily supplemented with substandard ore from the reserve warehouse 4. Sorting waste (pieces of ore with a uniform distribution of gold) is transported to the dump 3. The sorting product 8 (pieces with an uneven distribution of the valuable component) is processed: it is loaded into the crusher 9 for the next stage of grinding and the crushed ore mass is separated by the content of the valuable component 7 . The pieces with the balance gold content selected during the separation process 7 are sent to the processing plant 6 .

The volume of ore mass remaining after sorting 7 with off-balance gold content is supplemented with substandard ore from reserve warehouse 4 , thereby replacing the volumes of sorting waste 8 sent to dump 3 and the volumes of sorting product 7 sent to beneficiation plant 6. Then the next cycle of processing the ore mass is carried out, including its sorting according to the unevenness of the distribution of the valuable component 8 , grinding in crusher 9 and sorting according to the content of the valuable component 7. The cycles of processing the ore mass 8 - 9 - 7 with the replacement of sorting products 7 and sorting waste 8 with substandard ore from reserve warehouse 4 are repeated until the signs of uneven distribution of the valuable component in its pieces are lost.

The technical result of the proposed solution is an increase in the completeness of extraction of minerals from the subsoil, expansion of the mineral resource base of existing and planned mining enterprises.

Claims (1)

A method of open-pit mining of mineral deposits that includes identifying the uneven distribution of minerals in the subsoil, outlining the ore body, blasting the overburden and moving the blasted rock mass to dumps, blasting the ore body, primary sorting the blasted ore by size, content and uneven distribution of the valuable component in its pieces, forming a planned ore flow from pieces with a balance content of the valuable component, crushing and sorting pieces with an off-balance content of the valuable component in the presence of signs of uneven distribution, storing waste tailings, characterized in that before moving the blasted rock mass to dumps, part of the overburden located in the zone near the contact with the ore body is tested for the presence of the valuable component; if the content of the valuable component is over 25-30% of the balance content, these rocks are sent to a reserve warehouse for substandard ore; if when forming a planned ore flow, pieces with a balance content of a valuable component are supplemented with under-sieve product separated in the process of sorting the ore by size, and at the stage of sorting by uneven distribution of a valuable component in its pieces, substandard ore from a reserve warehouse is added to the rock mass, the sorting product - pieces with an uneven distribution of a valuable component are loaded into a crusher for grinding and the crushed rock mass is separated by the content of a valuable component, pieces with a balance content selected in the separation process are sent to the ore flow, while the cycles of crushing and sorting the ore mass are repeated until the signs of uneven distribution of a valuable component in its pieces are lost.