Parameters of hydraulic fracturing and disintegration of impervious rocks while preparing blocks for leaching

Conclusions 1. The maximum water injection pressure for hydrofracturing of Blyava ores was 12.1–12.9 MPa and for hydrodisintegration, 4.5–5.5 MPa. The calculated values of these pressures differ from the experimental ones by 20–25% and 25–36% respectively, which is satisfactory for natural-scale studies.2. The probability of hydrofracturing or hydrodisintegration of the mass depends a great deal on the distance between the packer and the borehole face. It has been demonstrated experimentally that hydrofracturing occurred at a distance of 0.1–0.6 m and only hydrodisintegration was noticed at a distance of 4–10.2 m. These data show that, all other conditions being equal, the packer (interpacker) spacing of the boreholes is of great importance for producing, in practice, some type of hydrodynamic impact on the rock mass.3. Water injection through boreholes into the ore body under conditions of hydrofracturing and hydrodisintegration showed the real possibility of establishing a hydrodynamic link between boreholes at distances of 5 m, 10 m, and greater.4. The technology and equipment developed by the Institute of Mining make it possible to prepare blocks of impervious ores for leaching by employing hydrofracturing and hydrodisintegration of rocks and creating in the block a borehole — slit — borehole system.5. As a result of suffosion of the ore, slime is released intensely from the drainage boreholes, which is typical for hydrofracturing and hydrodisintegration processes and for subsequent fluid injection under pressure. This may be used to augment the performance of the borehole — slit — borehole system.6. If conditions in the mining industry become favorable, it would be advisable to continue the operations, the essential features of which are elucidated in this paper.Translated from Fiziko-tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 5, pp. 100–105, September–October, 1996.     

Treatment of Mine Water by a Microbial Mat: Bench-scale Experiments

Abstract.   We investigated the treatment of acid mine drainage (AMD) by a blue-green algae-microbial consortium and substrate (containing powdered goat manure, wood chips, and soil) in 1 m³ bench scale biological treatment test cells. The microbial mat resulted from the interaction of bacteria and filamentous blue-green algae (predominantly Oscillatoria spp). The experiments were carried out for different water column heights, and were evaluated for 24, 48, 72, 96, and 168 hours of retention. Within 24 hours of retention, the pH increased from 2.93 to 6.78 as net alkalinity went from -125 mg/L to 197 mg/L as CaCO₃. Turbidity decreased by 33–54%, sulphate decreased by 23–29%, and hardness decreased by 19 to 26%. We also observed that: 95% of the Fe, 79–97% of the Cu, 84–86% of the Zn, 88% of the Pb, 59–83% of the Co, 22–62% of the Ni, and 28–45% of the Mn were removed. A blue-green algae/microbial mat consortium may be a cost–effective treatment technique for removing metals from AMD.     

Electrochemical interactions of industrially important platinum-containing minerals

Pt–Te₂ and Pt–Bi–Te are two important platinum-carrying minerals typically found in altered platinum reserves. Mineralogical studies indicate the Pt–Pd–Bi–Te class to react poorly on the flotation stimuli and indications are that these minerals are slow floaters. This paper investigates the fundamental interactions of potassium ethyl xanthate with these minerals by employing electrochemically controlled contact angle measurements, FT-IR spectroscopy and voltammetry. The electrochemical investigations revealed that Pt–Te₂ is more noble than Pt–Bi–Te at potentials lower than 300 mV (SHE) in sodium tetraborate buffer solution and the reduction peak observed during the return sweep of Pt–Bi–Te is mainly associated with the reduction of bismuth oxidation products. Both the minerals show increased anodic currents when polarised at 0.3 V (SHE) in a 0.05 M Na₂B₄O₇ solution containing 1 × 10⁻³ M potassium ethyl xanthate. According to the results of the rest potential measurements, formation of dixanthogen should be thermodynamically favourable and the very high rest potentials are attributed to the catalytic effect of platinum on the oxygen reduction reaction. The formation of dixanthogen on both the minerals was confirmed by ex situ FT-IR spectroscopy. Contact angle measurements revealed the surface of Pt–Bi–Te to be hydrophobic in nature whereas small contact angles were realized on Pt–Te₂. Surface roughness of the mineral could be responsible for these small contact angles.     

Pendulum-type waves. Part I: State of the problem and measuring instrument and computer complexes

Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 3–8, May–June, 1996.     

Division of supporting-pressure zones

Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 4, pp. 3–11, July–August, 1995.     

Breeze circulation in open-pit mines

Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 69–73, May–June, 1995.     

Study of caving features for underground workings in a rock mass of block structure with dynamic action. Part III. Analysis of the stability of an individual rock block in the roof of a working

Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 6, pp. 3–11, November–December, 1994.     

Determination of the real strength characteristics of precompacted soils

Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 22–26, May–June, 1995.     

Some features of the electromagnetic radiation signals during rock failure

The effect of quasi-resonance process appearing during electromagnetic radiation in the stage preceding failure of a rock sample is described.Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 20–28, May–June, 2004.     

Loading broken rock at open-pit mines with the use of vibrating equipment

Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 76–81, May–June, 1994.     

Electromagnetic precursor of rock failure

Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 12–13, May–June, 1994.     

Stress-strain state of rock near workings,in gravitational force field

Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 6, pp. 3–8, November–December, 1995.     

Effect of capillary condensate of methane on electrophysical and strength properties of coal

Mining Institute, Moscow. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 27–31, May–June, 1992.     

Fragmentation of a solid with repeated loading under weakening conditions

Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 31–36, May–June, 1995.     

New method of determining the operating parameters of a pneumatic percussion drill

Translated from Fiziko-Technicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 37–40, May–June, 1995.     

Regularities in the internal structure of diamonds of the malaya botuoba kimberlite field

Yakut Diamond Research Institute Yakutsk. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Polyznykh Iskopaemykh, No. 3, pp. 110–118, May–June, 1993.     

Prediction and means of controlling rock bumps at mines of the Northern Kuzbass

Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 82–84, May–June, 1994.     

Modeling the structure of fragmented and granular material: Three-dimensional problem

Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 35–38, May–June, 1996.     

Two-dimensional mathematical model of leaching dynamics for a cracked and porous ore mass

Far-East Branch, Russian Academy of Sciences, Magadan. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 87–95, May–June, 1993.