Gravel and sand are mainly needed in the construction industry. Due to increasing demands on the purity of building materials, it is necessary to wash and recycle gravel, sand, grit and other building materials. In their natural state, they are contaminated with contaminants such as loams, silts, fine particles, wood and coal. Therefore, water is used, which is soiled during the washing process. To be able to reuse it, the water has to be cleaned.
Conventional washing water treatment
In the conventional solution the soiled water flows into a tailing pond where coarse particles sediment. The roughly cleaned water is reused for washing, the rest is effluent which needs to be disposed. Furthermore, the tailing pond has to be dredged regularly with great effort.
Cost-effective and efficient washing water treatment and sludge dewatering
The lamella separator or lamella clarifier of Leiblein is reasonable, space-saving and efficient alternative solution for washing water treatment. The solids settle down onto the lamella packs and slide down into the sludge funnel. The clear water is led back into the washing process. To even raise the amount of clear water it’s possible to dewater the sedimented solids using the Leiblein vacuum belt filter. The vacuum belt filter is a reasonable and space-saving alternative to the frequently used chamber filter presses.
Our products are available to rent for pilot tests. Due to our extensive rental park, we can put together complete test systems individually for your task.
A modern treatment system for the processing of gravel and sand has been installed for Zwisler in Tettnang only a few kilometres away from the Bodensee. As products of high quality are manufactured by the company, a multi-stage wet processing plant had to be installed.
The natural water resources are very low and a treatment pond is not available. Therefore a wet processing technology, which reaches good washing results using small amounts of water, has been chosen. The treatment plant had to be compact, reliable, economical and inexpensive at once. For these reasons it was decided to install a water-treatment-plant from Leiblein GmbH.
The washing water of the wet processing system flows via a static mixing drain into a lamella separator. A flocculant is dosed previously.
The flocculated water flows evenly into the middle channel of the lamella separator and reaches the funnel region. During the subsequent upward flow the effluent passes the lamellas through which the flocks are separated. The purified water leaves the lamella separator of remarkably clear quality. The water flows into a floor tank and is reused for the wet processing.
The polymer is mixed by an automatic three-chamber-mixer and a batcher, which are installed in a 24 feet standard container. In order to export well dried sediment out of the lamella separator, the sludge exporter is controlled by an automatic sludge-level-measurement-device. The water which is released during post-thickening of the sediment can be reused as well.
This plant shows how high grade wet processing can be carried out using only small amounts of water.
Washing water of a railway treatment plant (System Knape GSG). The formation rehabilitation plant with a ballast treatment and washing system was fitted with a washing water treatment plant. The ballast is excavated, treated and washed and re-laid to the route at the end of the train.
During the ballast treatment method using a washing screen, the washing water is soiled with fine dirt particles as for example gravel abrasion, dust, soil and so on. The washing water treatment plant should separate those soilings from the water to allow a circuitry of the medium.
The effluent is pumped into the treatment plant, where flocculant is added to allow a better separation of fine particles before the water enters the lamella separator.
In the lamella separator the medium is led to the bottom and distributes below the lamellas over the entire lamella area. The medium flows through the lamellas to the top; the dirt particles settle onto the lamellas and slide into the sludge chamber. The purified water flows to the outlet on top of the lamellas. The separated sludge is exported by a scraper.The sludge is pumped into a sludge tank and disposed. The clear water is collected in a water tank and pumped by a slush pump to the gravel washing plant.
As the treatment plant had to be installed into a existing mobile track machine the individual constructional conditions had to be considered for the construction. Due to their great experience in the field of special plant construction Leiblein GmbH successfully concluded this project.
The surface water occurring at a stone quarry is polluted with fine mineral particles and is to be treated before discharge.
The surface water is transported to a pump sump through existing chutes. A pump with a capacity of 72 m³/h constantly pumps the water to the lamella separator. Excess water, resulting from heavy rainfall is led directly into the river via an emergency overflow.
The mineral particles are separated as sludge in the Leiblein lamella separator. The purified water flows via the existing settling basin to the discharge system. The sludge from the lamella separator is exported from time to time and removed with a wheel loader.
The lamella separator as an example for ideal recovering of fine sand. Rinsing water is used for the wet-treatment of sand. The water contains large amounts of residual fine sand. The sand extraction offers the following advantages:
The washing water which is polluted with fine sand and other dirt particles is pumped into the lamella separator. The clarifying area load was chosen so that only particles larger than a certain size a separated. Fine particles as for example clay leave the separator with the treated water.
The separated sand is collected in the sludge funnel and dewatered by a sieving plant.
Washing water circulation without flocculant in a gravel mill with a lamella separator. For the production of high quality concrete chipping large amounts of washing water is needed. The washing water can be recirculated when continuously treated. A particularly suitable appliance is the lamella separator.
The washing water, polluted with fine particles and mineral parts, is led into the lamella separator and the particles are separated by the inclined honeycomb lamellas. The clarified water is led back into the water circle.
The separated sludge particles form a sediment in the sludge funnel and can be exported by a pump. A supporting stirrer which prevents the sludge from caking can be fitted.
Remarkably, an addition of flocculant is not necessary and therefore the water is not subject to chemical modifications. For further drying Leiblein can recommend additional processes if required.
In this case a good separation result was reached with a clarifying area load of less then 0,7 m/h.
|Clarifying area lamella separator||150 m2|
|Solids contentd||max. 2t/h|
|Sludge volume||ca. 6,5 m3/h|
At a throughput of 100 m³/h and a clarifying area of 150 m² results a clarifying area load of ca. 0,67 m/h. The sediment consists of approx. 30% of fine grit and 70% of mineral parts. The solids content of the separated sludge is around 30%.