SU1744595A1 - Method of disintegrating sedimentary rocks - Google Patents

Abstract

The use relates to geology, and specifically to methods for preparing sedimentary rocks for particle size analysis. The essence of the invention: in the clay-carbonate composition of cement, disintegration is carried out by preliminary determining the size of the rock grains, crushing it to a size not lower than the maximum grain size, soaking and dispersing. Soaking is carried out in distilled water. In this case, the rock is subjected to a series of cycles of soaking and drying in air until the appearance of individual clay particles on the rock surface.

Description

The invention relates to geology, and in particular to methods of preparing sedimentary rocks for lithological studies.

Closest to the proposed is a mechanical method of disintegration, which is carried out manually or automatically. Very dense argillites, siltstones are pre-crushed. In order to avoid overgrinding of terrigenous minerals, a fraction less than 0.5 mm is sifted out, and a class of 0.5-2.0 mm is selected for soaking for 1 day. Then, by rubbing the water with a rubber pestle, this class is suspended. The suspension is subjected to dispersion prior to the purification of sandy-silty mineral grains from cementing particles (checked under a magnifying glass).

However, with this method of disintegration of dense samples with clay-carbonate cement during dispersion

rock class 0.5-2.0 mm is subjected to intense mechanical stress. As a result, along with the separation of fine fractions, larger particles are abraded, the size and morphology of the mineral grains are not preserved, and, consequently, the grain size distribution is distorted.

The purpose of the invention is to increase the efficiency of disintegration of rocks with a clay-carbonate composition of cement by eliminating the grinding of grains while maintaining the perfection of the structure of minerals.

The proposed technical solution is based on the weakening of the cementation strength, as a result, when dispersing, the intensity of the mechanical action decreases, the particle size grains are not frayed, the fine fractions with

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better preservation of the perfection of the structure of minerals.

The method is carried out as follows.

In the thin section, the sizes of maximum grains are preliminarily determined. The sample was then crushed so that the pieces were uniform in size and approached the maximum grains of the rock. The class below the maximum grains is screened out, the class above the maximum grains is selected for a series of soaking cycles in distilled water and drying in air prior to dividing individual clay particles on the rock surface. Pieces of rock become soft, hard or prickly to the touch. Rocks in the first two aggregate states are further disintegrated by dispersing them in water before cleaning the grains of minerals from cement.

The difference between the proposed method and the known one is that the rock is subjected to a series of soaking cycles in distilled water and drying it in air until clay particles appear on its surface.

The advantage of the proposed method for samples with a clay-carbonate composition of cement over the known mechanical disintegration methods is as follows: upon repeated soaking and drying of the rock, the effect of clay particles on its surface is obtained, and their minerals have a perfect structure; when dispersing the rock in water, the intensity of the mechanical action decreases, the grains are not rubbed, they retain their shape and size, therefore, the accuracy of the selected granulometric spectrum of the rock is improved; the number of samples susceptible to disintegration is increasing.

The technical and economic effect of using this method in disintegrating rocks with a clay-carbonate composition of cement consists in expanding the field of ligological research. The mechanical and chemical methods of disintegration used do not correspond to the set task, since the use of mechanical methods distorts the particle size distribution, and the use of chemical methods worsens the perfection of the structure of minerals, many of them dissolve.

Example 1. The implementation of the method in particle size analysis on the example of sample No. 200.

Microscopic examination of the thin section showed that it is aleurolite, lime-clay cement, the largest grains do not exceed 0.5 mm.

The sample is crushed into pieces not less than 0.5 mm, larger pieces are selected and again

crushed. When the crushed mass becomes uniform, a class of 0.5-1.0 mm is screened out for soaking.

A soak of 50 g is produced with 200 ml distilled water.

0 Breed swells, then dried in air for 6-8 days. After four cycles of soaking and drying on the surface, a clay suspension appears, the pieces feel soft to the touch. After that, the sample was again poured with distilled water, mixed well, and after 1 day of settling, the water with soluble salts was separated.

Next, the dispersion of the breed is carried out in a small amount of distilled water in the cylinder with a rubber pestle for 15 minutes. To avoid overgrinding of clay minerals, the subsequent separation of particles is carried out.

5 less than 0.01 mm according to the Sabanin method. Dispersion and separation of particles less than 0.01 mm are repeated many times until clay slurry is released. Then by successive sieving with a sieve of 0.5, 0.25, 0.1 mm, the granulometric fractions are separated: 1.0-0.5 mm, 0.5-0.25 mm, 0.25-0.1 mm . At the same time, in succession, each fraction is checked under a magnifying glass for completeness

5 cleaning the grains of minerals from cement. If the rock aggregates are not completely disintegrated, the fraction is placed in a porcelain dish and rubbed with a rubber pestle until a thick suspension is released. Then this fraction is sieved through a sieve corresponding to it.

After separation of the sandy fractions, the clay – silt suspension 5 less than 0.1 mm is combined with the clay suspension less than 0.01 mm, obtained by disintegration by dispersion in order to further separate the suspension into a silt and clay

0 fractions by hydraulic methods of particle size analysis.

Under a microscope, the morphology of the grains in thin sections and aleurolite granulometric fraction is compared. Comparison

5 showed that both in the thin section and in the 0.1–0.05 mm particle size fraction, the aleurolite particles are represented by angular and semi-rolled grains. This allows us to conclude that the granulometric composition of the densely cemented area was obtained. 17445956

of sample no. 200 with preservation of the morphology of the green disintegration by this method and the breed is mentioned. manual mechanically.

Example 2. Sample

Claims (1)

No. 433. Invention Formula. For a qualitative comparison of the methods5, the method of disintegration of sedimentary disintegration for the purpose of studying fine rocks, including the determination of the poorly cemented sample size of rock grains, crushing the rock to a clay-carbonate composition of cement size not below the size of the maximum decomposition by two methods, soaking, dispersion, about t these: manual mechanical and proposed. 10 due to the fact that, in order to increase, the proposed method ensures the yield efficiency of the method with clay -carbon fractions with better preservation of co-bonate composition of cement, rock under the structure of minerals, a series of soaking cycles shows the intensity of distilled water refluxes and drying on minerals when comparing X-ray 15 to air before the appearance of porous 0.001- 0.005 mm, obtained by adding individual clay particles.