Contact us for Polymers for Sand, Gravel, Aggregate and Concrete Processing

concrete processing

Contact us for samples!

Polymers for sand, gravel, aggregate and concrete processing are applied extensively. They are also used for dredging projects in our rivers lakes, streams and harbors to promote efficiency, safety and economy of operations. The old saw goes, “if you don’t grow it, then you have to mine it.” Mining metals and minerals requires polymers for sand, gravel, aggregate and concrete processing. When we move around the contents of the earth’s crust with our heavy machinery, we make fines, finely divided particles which have to be collected, captured, refined or segregated in some fashion to allow for economical and environmentally friendly commercial operations. Polymers for sand, gravel, aggregates and concrete processing allow for an efficient on economical handling of the minerals and their incumbent fines. It is useful to describe the types of processes and equipment commonly found on such processing operations and plants.

PDF for Dewatering System Graphics and Charts

PDF for Aggregates/Sand & Gravel Washing Polymer Additions

Polymers: Thickeners

We might first look at the fines produced from hydrocyclones which remove the large particles, the “bricks and bowling balls” from the raw feed of mineral. The fines exiting the hydrocyclone are successfully agglomerated with coagulants such as the Tramfloc® 500, 700 and 800 series of formulations before the fines are pumped to the thickeners, sometimes referred to as clarifiers. The coagulants can reduce the TSS and turbidity of the clarified water. Then anionic flocculants such as the Tramfloc® 100 series of formulations are often fed to the thickener influent to effectively settle fines. Then polymers for sand, gravel, aggregate and concrete processing such as the Tramfloc® 100 series of formulations are fed to the influent of a dewatering device such as a belt filter press or a screw press or centrifuge. In this fashion a high solids content cake is produced by the dewatering equipment. This helps make the plant operations cost effective and efficient. From the dewatering equipment we can then produce high quality filtrate, clarified or cleansed water, for reuse. In this manner than the plant can reduce or eliminate its purchased or pumped water requirements. Water is becoming increasingly scarcer and more costly, especially in the western USA. Polymers for sand, gravel, aggregate and concrete processing, coagulants that is, are typically fed before the thickeners in the 1-5 ppm range while polymers for sand, gravel, aggregate and concrete processing flocculants, that is, are typically fed in the 2-10 ppm range.

Polymers: Sand Processing – Dry Process

Next we might review the objective of separating the ultra fine suspended solids in the raw sand. These solids typically do not settle effectively by themselves. Polymers for sand, gravel, aggregate and concrete processing are frequently required. If clays are present in the finely ground material, there are potential quality control difficulties and many concrete and aggregate plants have clay limits in the finished product. Clays can be troublesome and common types encountered are: Bentonite, Illite, Montmorillonite (red clay) and humic acid. The latter species comes from old forests and when present may need a special type of polymers for sand, gravel, aggregate, concrete processing the Tramfloc® 860-899 series of coagulants. Occasionally Ca(OH)2 and CaCl2 are useful in humic acid conditions. Our technical bureau should be consulted if humic acid is identified.

Concrete requires a very low concentration of silt particles, 75 microns in size, to maintain effective engineering properties in the finished product. Fine sand washing removes the silt as a waste product.
Sand Processing – Fine Sand Washing – Wet Process

Polymers for sand, gravel, aggregate and concrete processing can be quite useful in achieving the objectives of fine sand washing. They are to remove the undesirable silts and to separate the fines into the grades specified by the plant operator. It is in the undesirable silts that the slurries originate.

Polymers: Clarification in the Thickeners

Polymers for sand, gravel, aggregate and concrete processing are very effective in performing their task of settling solids rapidly and thoroughly in the thickeners. Polymers for sand, gravel, aggregate and concrete processing can also be applied to wastewater/washwater ponds, lagoons, rectangular settling tanks, Baker tanks and the like but with less engineering efficiency that in conventional thickeners. Thickeners are more cost effective than the aforementioned alternative vessels. Plant management incurs high maintenance costs for mucking out ponds and hauling solids when not installing thickeners. Occasionally plants use the alternative vessels without polymers for sand, gravel, aggregate and concrete processing with acceptable results.

Polymers: Dewatering

A belt filter press, BFP, is cost effective piece of equipment that produces a high solids content cake of the undesirable silt fines. Polymers for sand, gravel, aggregate and concrete processing are very effective in producing high throughput on the BFP, generating low solids filtrate for recycling and capturing a high percentage of solids from the raw mud fed to the press or other dewatering device. When plants pump mud to the lagoons and the like, management reports that maintenance and labor costs are high.

Polymers: Dredging

Dewatering of dredgings is an important application for polymers for sand, gravel, aggregate and concrete processing. Dredging is required when waterways such as lakes, streams, rivers and harbors have accumulated naturally flowing silts, mud and run-off. This makes the estuary or water body less productive for commercial and recreational purposes. Dredgings are commonly pumped up to a barge equipped with a piece of dewatering equipment such as a BFP. Polymers for sand, gravel, aggregate and concrete processing are usually applied to the flocculator section of the BFP and polymers for sand, gravel, aggregate and concrete processing such as Tramfloc® 300 Series formulations are ofter applied in the 60-180 ppm range to effectively dewater the dredgings. If dredgings are pimped to a thickener for clarification, as per the engineer’s specification, then polymers for sand, gravel, aggregate and concrete processing such as Tramfloc® series of formulations are effectively applied.