Parameters of selective martite ores disintegration in structured ore bodies deposits by borehole hydraulic monitors

The work is aimed at determining parameters of advance borehole stoping by hydraulic monitors leading to rational use of reserves structured according to ore types at deposits by means of advance stoping with selective disintegration of high-grade martite ores. The research methods include experimental investigations of parameters of breaking a high-grade martite ore massif by high-pressure water jets of borehole monitors; laboratory studies of technological properties of hydrodisintegrated products and their concentratibility; theoretical generalization of experimental data. The research has resulted in developing experimental borehole hydraulic monitors and determining basic technical parameters of high-pressure water jets; determining regularities of hydraulic monitor disintegration of high-grade martite ores considering structural and mineralogical characteristics of the ores and hydrodisintegration modes; proving the fact that the process of high-grade martite ore disintegration by monitors is also the process of ore disintegration to the level of ore mineral grain release providing the higher quality disintegration product after subsequent dewatering than that of the initial one. The scientific novelty of the research consists in determining a criterion of hydrodisintegration of martites, conditions of forming a required fractional composition of monitor disintegration products through controlling stability of a pulse of the water jet action on the stope face. The practical relevance of the monitor breaking process in conditions of mining units at deep levels of Kryvbas underground mines consists in providing advanced stoping of rich martite ores through raises and obtaining a new kind of product – martite superconcentrate.

IRON 60

The long-lived radionuclide Fe60 has been observed through extraction of its disintegration product, 10-minute Co60m, from the iron fraction isolated from a copper target bombarded with ~400-Mev. protons. Direct observation was prevented by the Fe59 present. Yield considerations indicate the Fe60 half-life to be ~3 × 105 years, uncertain by a factor of 3.

Structural Changes in Rubber Brought about by Molecular Oxygen. III. Properties of Disintegrated Vulcanized Natural Rubber

1. The product of destructive solution of vulcanizate contains 50 mg. of oxygen per gram of substance; of this quantity, 3.77 mg. falls to the share of oxygen contained in free carboxyl groups. 2. The disintegrated vulcanizate is soluble in ordinary rubber solvents, as well as in binary mixtures of associated and unassociated liquids. 3. The viscosity and light diffusion of a broad range (up to 6 per cent) of disintegrated vulcanizate solutions are linear functions of the concentration. 4. The average molecular weight of the disintegration product of a vulcanizate, as determined from the coefficient of diffusion, is 3600; according to the viscometric and optical data, the molecules represent very large, elongated entities with an axial ratio of 1:24. The distribution curve of diffusion coefficients has a sevenfold dispersion. 5. The mechanical strength and elasticity of films prepared from a disintegrated vulcanizate are very much lower than those of films made of vulcanized rubber.