<p>Mine mining is usually pided into sub-underground mining and open-pit mining; and the characteristics of mining machinery are as follows:</p>
<p>1. Due to the limited space of mine, mining machinery is asked to be compact in body, small in size, and thus the pressure and load that bearings and gears endure are big;</p>
<p>2. The working conditions and load of mining machinery are changeable, so it should be moveable;</p>
<p>3. Mining machinery are mostly work in heavy-duty or medium-speed or low speed transmission, most of which require frequent starting and often withstand impact loading;</p>
<p>4. The mine environment is harsh and wet with rock dust, coal dust and gas (main component is methane) and some mines are with harmful gases containing sulfur (sulfur dioxide, hydrogen sulfide), so many of the mining machinery have to be fire-proof, explosion-proof and anticorrosive;</p>
<p>5. Many impact crusher or
Ore Milling Equipment are working out of door, so the open-air mining machinery should be able to withstand wind, sun, rain and climate change such as hot in summer and cold in winter;</p>
<p>6. due to small mine space, machine maintenance is more difficult than that in ground, thus requiring mining machinery to be durable and easy-to- maintain.</p>
<p>The characteristics of the mining machinery make the following requirements to lubricants:</p>
<p>1. The volume of mining machinery and tank are both small with little amount of the lubricating oil and the oil temperature is higher when machine is working, which requires lubricants have good thermal stability and oxidation resistance;</p>
<p>2. Because the harsh environment of the mine-- coal dust, rock dust, more water-- lubricating oil is bound to be polluted by these impurities, so it is requested that the lubricant should have good anti-rust, anti-corrosion, anti-emulsifying properties; the performance change of lubricant should be small if contaminated, that is, sensitivity to pollution is small;</p>
<p>3. The temperature in summer and winter or day and night varies greatly, thus open-pit machinery require the lubricant viscosity varies small with temperature—so it is necessary to avoid too low oil viscosity leading to difficulty in forming a lubricating film and cannot achieve the lubrication role in high temperature; but also to avoid starting and operation difficulties because of too high viscosity in low temperature;</p>
<p>4. For some certain mining machinery, particularly used in the place where prone to outbreak of fire and explosion, mine machinery is required to use good lubricant (fire resistant fluid) with good incombustibility, cannot use combustible mineral oil.</p>
<p>5. Lubricant should have good adaptability to seals better in order to avoid seals being damaged.</p>
