Underground all mining machinery and safety shields are operated hydraulically. A hydraulic circuit can extend up to several kilometres and is operated with up to 350 bars in the feed line. The hydraulic fluid must be free of particles in every part of the circuit. Pollution of hydraulic fluids leads to lengthy and extremely costly failures.

Filtration at high pressure pumps

Our automatic high-pressure filter units and the automatic double back-flush filters are systems that serve for the filtration of freshly prepared hydraulic emulsions directly behind the high-pressure pump. These filter systems are designed for working pressures of 350 bar and higher.

HFA/HFC filtration

As with other heavy duty industries where high temperatures are present close to working machines, the use of flame retardant hydraulic fluids is mandatory in the mining sector. The fluids used in mining are either luids with very high water content (type HFA made from 80% – 90% water and mineral or synthetic oil) or fluids with lower water content (type HFC made from 20% -50% water and glycol). Hydraulic fluids require a stable ratio of water and organic phase in order to function properly. Consequently, our filter media are precisely adapted to the fluid to be filtered in order to make de-mixing of lubricant and water impossible.

Filtration in hydraulic circuits

In order to ensure the failure-free operation of hydraulic systems underground, it is essential that the medium is not simply filtered at one point, but is continually cleaned throughout the entire circuit. Thus, return filters, that clean the fluid coming from the mining machines, are essential parts of the circuit. Return filtration is often carried out in two stages that are individually adapted to the respective application. In the first stage, an economical and effective pre-filter retains the larger part of any impurities, while in the second, our Long-Life elements ensure the provision of a fluid that meets the specified level of purity.
In addition to high-pressure and return flow filtration, bypass filters help to keep hydraulic fluid in the tank clean and in motion at all times.