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- Spray drying polyaluminum chloride -- Chinafloc-PAC
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In the treatment of the coal washing wastewater, the anionic polyacrylamide product is normally used as the flocculating agent for the treatment of the wastewater which is brought from the washing process of the regular coal.
The coal washing wastewater contains huge amount of the suspending particles, coal slime and sands, therefore, it is commonly known as the coal slurry.
Some fine coal powder can suspend in the coal washing wastewater very stably, especially the ultrafine coal powder, they could suspend in the wastewater and stand in the water for months and will not be naturally deposited.
To solve this problem of the suspending coal slime and the sands in the slurry, we need to use the coagulant and the flocculant together for the better effect.
The Solution One: To use the PAC and the PAM together
The selection of the PAM molecular weight:
In most cases, we recommend the use of the anionic polyacrylamide with the conventional molecular weight, in between 1,800 x 104 and 2,500 x 104. Usually, we need to do the primary trial application or the choice experiment to determine the best value of the final anionic polyacrylamide specification. The PAC (polymerization aluminum chloride) will be added first, and then the anionic polyacrylamide will be put in.
The Solution Two: To use the Lime and the PAM together
The sedimentation method by using the lime with the anionic polyacrylamide can achieve better effect on the treatment of the coal washing wastewater, however, some points needs to be emphasized which could influence the treatment effect, that is the dosing method of the lime, the property of the anionic polyacrylamide and the dosing sequence of the lime and the anionic polyacrylamide, especially, the dosing sequence is different from the traditional adding sequence.
With the use of the anionic polyacrylamide with the suitable molecular weight, the wastewater could be clarified promptly and efficiently.
The traditional treatment method is to use the lime with the anionic polyacrylamide, but its shortcoming is that the lime may have some impact on the effect of the anionic polyacrylamide.
Now, we usually use the Solution One, that is to use the coagulant with the organic flocculant which can achieve very distinct effect on the wastewater treatment.
According to the density of the suspending impurities in the coal washing wastewater along with the properties of the coal, the molecular weight of the anionic polyacrylamide could be selected from the value between 1,000 x 104 and 2,000 x 104, which will achieve the better treatment effect.
The effect of the flocculant in the treatment of different mining processing wastewater and slag
During the treatment of the mining processing wastewater and slag, the selection of the flocculating agent type is flexible along with the variety of the minerals’ elements. The flocculating agent is classified as the cationic type, the anionic type and the nonionic type. Under the regular circumstances, we usually choose the anionic polyacrylamide flocculating agent for the common minerals.
The characteristics of the mining processing wastewater:
The wastewater from the mining processing figures a large amount of waste water and the severe pollution. The major pollution substance in the waste water is the suspending materials such as the clay and the mineral powder etc, and the floatation reagents.
In the mining processing, it contains the poisonous inorganic materials, all sorts of metal ions such as the mercury, the cadmium, the lead, the chromium, the arsenic, the copper, the zinc, the cobalt and the selenium etc., it also has the the cyanide, the fluoride and the other dissolved salts.
The flocculatiing agent of the cationic type, the anionic type and the nonionic type has a broad range which can meet all kinds of needs in the treatment of such mining processing wastewater.
The function of the flocculating agent:
The polyacrylamide flocculating agent can absorb the solid particles which are suspending in the waste water, it can make the particles agglomerate and make them form the large flocs by the bridges between the particles or by the charge neutralization. Therefore, the polyacrylamide flocculating agent can accelerate the sedimentation of the suspending particles in the liquid, with obvious effect in the acceleration of the solution clarification and the filtration promotion.
The polyacrylamide flocculating agent can work in different roles in various applications.
1.The polyacrylamide flocculating agent works as the sewage sedimentation agent
It can be used in the urban sewage treatment, the paper making industry, the food processing industry and foodstuff industry, the petrochemical industry, the metallurgical industry, the mining processing industry, the dyeing wastewater treatment industry, the sugar industry and the other various industrial wastewater treatment etc.
2.The polyacrylamide flocculating agent can work in the paper making industry as the paper dry strength agent, the retention agent and the filter aid.
3.The polyacrylamide flocculating agent can work as the decloloring agent in the dyeing industry and the paper making industry.