OJSC Uralmekhanobr (a research and design institute as part of UMMC) has developed a new composition of filling mixtures for the Magnesitovaya mine of the Satka production site of the Magnezit Group (Chelyabinsk region, Satka).
Previously, the extraction of magnesite in the mine was carried out by a chamber-and-pillar mining system. The tailings and waste rock were used as dry stowing mixture. At the same time, up to 35% of the ore remained in the pillars between chambers, which is not economically viable.
As a result of the research, it was decided to transfer the mine to a chamber development system with backfilling of the mined-out space with hardening mixtures. The new method will make it possible to fully extract mineral reserves, while maintaining the reliable stability of the earth's surface.
- We were faced with the task of developing a new composition of hardening mixtures in strength that meets regulatory requirements, which is able to ensure a stable state of the filling mass. As a result of the use of such mixtures, the safety in mining operations will increase and the efficiency of field operation will increase, - noted the head of the mining science department of Uralmekhanobr OJSC Yuri Dik. 9 months. Specialists of the department of mining science "Uralmekhanobra" investigated two technologies for preparing such mixtures: mill and millless. The essence of the mill technology is that all components of the filling mixture are crushed and mixed in a ball mill. Mill-free technology implies the use of pre-crushed components, the mixing of which occurs due to the use of special mixers.
The studies have shown that under the operating conditions of the Magnesitovaya mine, it is advisable to use mill technology, because the technological indicators of the filling mixtures in times higher. The mixtures have a more homogeneous and plastic consistency, which allows them to be transported in gravity mode over sufficiently long distances.
As an inert aggregate, it was decided to use ground dolomite of fraction from 0-5 to 0-20 mm, a simple binder cement became a substance, and cement in combination with finely ground slag became a complex binder.
The technology for preparing hardening mixtures proposed by Uralmekhanobra specialists is currently being implemented at the Magnesitovaya mine.
