Groundwater problems in surface coal mining in Scotland

The paper reviews the problems encountered with groundwater in surface mining in Scotland. The problems which occur at various stages of the mining process from initial exploration to mine planning and final restoration are referred to. Special consideration is given to mine drainage and pumping methods.     

Using new physics and technology to advance electrostimulated rolling of metals and alloys

Electrostimulated deformation of metals and alloys, using groove or smooth rolling, requires that several important conditions are satisfied. (1) The deformation site must geometrically overlap with the flow of electric current passing through a strip between the rolls; (2) The density of direct or alternating electric current supplied to deformation site must be sufficiently high (of an order of 104-106A/cm2 ); (3) An efficient heat removal from the deformation site must be achieved. In general, the temperature of a strip must be within the range of 100-300℃. (4) The electric resistance at the roll-strip interface must be minimized. Our recent studies also indicate that the electrostimulated rolling in the shortcut regime is a further condition for obtaining high quality rolling of metals. In this regime, the rolls are placed in physical contact even in the absence of a strip that ensures an uninterrupted passage of electric current between the rolls.Provided that the aforementioned conditions are met, the plastic rolling deformation of various metals and lloys, including the most refractory and deformation resistant ones such as tungsten, molybdenum,their allows with rhenium, becomes possible. A single pass through the rolls is usually sufficient to deform a strip by about 50%- 70% as is the case for tungsten. Significantly, the temperature in the deformation site does not exceed 150-200℃.In our opinion, excellent results for electrostimulated rolling obtained by us are related to new previously unknown behavior of metals and alloys, being subject to pressure treatment and rolling.     

On the anisotropic character of material hardening during loading with partial unloading

Mining Institute, Siberian Branch, Academy of Sciences of the USSR, Novosibirsk. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 6, pp. 57-64, November-December, 1991.