Qualitative characteristics and physical and mechanical properties of gypsum stone from the Zuevsky deposit

The article provides information on gypsum deposits in the Perm region. The need of various industries for gypsum is described. The purpose of the work is to determine the qualitative characteristics and physical and mechanical properties of gypsum rock. The geological structure of the Zuevskoye deposit of building gypsum is given. A description of the useful strata is given, divided into sections and types of deposits, as well as a description of the internal overburden. The qualitative characteristics of the mineral are given based on the results of geological exploration. The quality of the gypsum is assessed based on the main evaluation parameters corresponding to the requirements of the main regulatory documents: GOST 4013-82 “Gypsum and gypsum-anhydrite stone for the production of binders”. Specifications and GOST 125-79 “Gypsum binders”. Specifications. To determine the suitability and grade of the gypsum, the chemical composition was determined. Calculations of average weighted contents of chemical components were performed for enlarged intervals equal to half of the mining bench (5-7 m). In addition, the physical and mechanical properties of gypsum rock were determined: water absorption, bulk density, specific gravity, volume porosity, true porosity, and ultimate strength in a dry state. Based on the results of the work, it was revealed that the chemical composition of the gypsum layer of the Zuevsky site is diverse, which is caused by uneven hydration of anhydrites in plan and in section, as well as the presence of various carbonate impurities and karst. Gypsum of the Zuevsky site is heterogeneous in its physical and mechanical properties. The strength of gypsum in air-dry averages to 16.9 MPa, and in accordance with GOST 125-79, gypsum rock has a grade of G-16. The raw materials of the gypsum thickness meet the requirements of GOST 4013-82 “Gypsum and gypsum-anhydrite stone for the production of binders” and GOST 125-79 “Gypsum binders”. According to the complexity of the geological structure, the Zuevskoye deposit is assigned to group II. The useful thickness in the area is extremely unstable in thickness and quite consistent in quality.