The natural types of ores are diamondiferous kimberlites and diamondiferous lamproites, which are subdivided on the basis of the proportions of kimberlite itself and xenogeneic material and structural and texture features, on diamondiferous massive kimberlites, kimberlite breccias, tuff breccias, xenotubrubricchia, tuffs and tuffaceous sedimentary rocks.
There is no uniform technological classification of diamond-bearing ores. In the technical and economic typification of ores, two main technological types are distinguished: breccias with a clay content of less than 20% and breccias with a clay content of more than 20%. When processing these ores, both technological schemes and the cost of mining differ.
In general, as practice shows, the technological classification of ores is developed in each case independently during the exploration and subsequent exploitation of the deposit. Often, when the kimberlite body is composed of rocks of different phases of implantation, clearly differing in structural and texture features and the level of diamond content, the natural types of ores practically coincide with the technological ones. The main factor is the content of diamonds. Thus, in the Dalnyaya tube (Sakha-Yakutia) two natural types, kimberlite breccias and massive kimberlites, are distinguished here in terms of the level of diamond content by an order of magnitude and are also technological types. However, for example, during the operation of the Mir tube, six technological types of ores were distinguished, differing in nuances of structure and diamond content, whereas there were only two implant phases.
Technological types of diamond-bearing sands are isolated, based on their ripeness, clayiness, rinsing, etc.
Natural and technological types of graphite ores.
The graphite ores are typified by texture-structural features. Graphs are divided into explicitly and cryptocrystalline. Among the clearly crystalline isolates are denser-crystalline and scaly varieties. The dense graphite graphite is subdivided into coarse-grained graphite with an average crystal size of more than 50 μm and fine crystalline.
By the size of the scales, their diameter, flake graphites last for coarse-scaly (100-500 microns) and finely scaly (1-100 microns).
The cryptocrystalline graphites are composed of crystals having a value of less than 1 μm. Dense and finely dispersed or diffuse differences are distinguished. In the latter, the crystallites of graphite are scattered in the host rock. In dense differences, the graphite crystals form the bulk of the graphite rock. Only dense differences of cryptocrystalline graphite have an industrial significance.
On the level of carbon content, natural graphite consists of six commodity groups (%):
– crystalline lumpy – 92-95;
– crystalline large-scaly – 85-90;
– crystalline medium-scaly – 85-90;
– crystalline small-scaly – 80-90;
– crystalline powders with a size of up to 0.074 mm and graphite carbon content of 80-99.
Exploration of graphite deposits of other industrial types, having deposits of irregular shape or lenticular and rod-shaped, is also carried out by core drilling wells in combination with mine workings.
When assessing and exploring graphite deposits using drilling, the absence of selective core attrition is established, which is possible with an uneven distribution of graphite concentrations, in the form of enriched areas represented by a network of veins, lenses, nests, and the like. For this purpose, the graphite content in the drilling mud and slurry should be monitored. If necessary, pass checks with gross testing.