How To Improve The Filtering Effect of The Filter Press?
As a commonly used solid-liquid separation equipment, the filtering effect of the filter press is mainly related to the properties of the slurry, the properties of the filter cake, the pressure difference of the filter medium, and the degree of vacuum. In the production process, starting from these aspects, the filtration effect of the filter press can be effectively improved.
1. Improve slurry properties
A. Increase slurry concentration
The productivity of the filter press increases as the slurry concentration increases. Therefore, the slurry concentration can be appropriately increased, and the productivity of the filter press can be improved. Usually, most processing plants require slurry concentration greater than 40%.
B. Reduce fine-grained material in slurry
There are more fine-grained materials in the slurry, so the filterability of the slurry is poor. In production, coarse-grained materials can be “incorporated” into the fine-grained slurry, thereby changing the particle size composition of the filter press cake and improving water permeability. It is also possible to use a coagulant to agglomerate the fine ore particles into flocs, forming a loose filter cake on the surface of the filter cloth.
C. Specific analysis of flotation reagent properties
The flotation reagents contained in the slurry are complex. Most flotation reagents reduce the filterability of pulp, and only a few flotation reagents improve filterability. Therefore, the filtering effect of the flotation agent on the filter press should be judged according to the type, nature, and dosage of the flotation agent used.
2. Change filter cake properties
The properties of the filter cake mainly include filter cake porosity, filter cake resistance, filter cake cracking, etc. The larger the filter cake porosity, the lower the filter cake moisture.
The resistance of the filter cake will affect the filtration and dehydration speed of the filter press. The filter cake resistance mainly depends on the filter cake porosity, thickness, and slurry viscosity. In operation, it is necessary to keep the thickness of each part of the filter cake layer uniform, so that the resistance distribution of the filter cake is uniform.
3. Use a suitable pressure difference
Generally, the finer the particle size of the material in the slurry, the greater the required pressure. However, if the pressure difference is too high, the damage to the filter medium will be accelerated and the power consumption will be increased.
4. Reasonable selection of filter media
The filter medium usually adopts cotton filter cloth or fiber cloth. In the process of filtration and dehydration, the clogging of the filter cloth will inevitably affect the productivity of the filter press. The filter cloth is blocked because of mechanical blockage, and the sediment generated by the chemical reactions causes blockage. When the filter cloth is seriously blocked and affects productivity, it needs to be cleaned or replaced in time.
It is recommended that filter media be selected according to the following requirements:
A. High recovery rate for filter material.
B. Small filter resistance.
C. Meet certain mechanical strength requirements, durable.
D. Not easy to block, easy to clean.
E. Easy installation and disassembly.