Polyferric sulfate is a kind of inorganic polymer coagulant with superior performance. It is light yellow, amorphous powder solid, easily soluble in water. 10% (mass) of aqueous solution is reddish brown transparent solution with hygroscopicity. Polyferric sulfate is widely used in the purification of drinking water, industrial water, various industrial wastewater, urban sewage, sludge dewatering and so on.
Chinese name of chemical: polyferric sulfate, solid polyferric sulfate (SPFS for short)
Molecular formula: [Fe2 (OH) n (SO4) 3-N / 2] m (where n < 2, M = f (n))
Technical specification code: bk-113-06
Harmful component: ferric sulfate (polymerized)
Content of ferric sulfate: 20-21%
CAS No. ： 35139-28-7
Main ingredient: ferric sulfate
Appearance and properties: yellow or reddish brown amorphous powder or granular solid.
PH (10g / L aqueous solution): 2-3
Melting point (℃): 190 (253kpa)
Boiling point (℃): no data available
Relative density (water = 1): 2.44
Relative vapor density (air = 1): no data
Saturated vapor pressure (kPa): 0.13 (100 ℃)
Solubility: soluble in water, alcohol, chloroform, carbon tetrachloride, slightly soluble in benzene.
Characteristics of polyferric sulfate
1. New type, high quality and high efficiency inorganic polymer flocculant of iron salts;
2. Excellent coagulation performance, dense alum and fast settling speed;
It is also harmless to heavy metal ions and aluminum ions, and has no harmful effect on water;
4. Turbidity removal, decolorization, deoiling, dehydration, bacteria removal, deodorization, algae removal, COD, BOD and heavy metal ions in water are significant;
5. The pH range of the water body is 4-11, and the range of pH value is 6-9. After purification, the pH value and total alkalinity of raw water change little, and the corrosion to the treatment equipment is small;
6. It has obvious effect on micro polluted, algae containing, low temperature and low turbidity raw water, especially for high turbidity raw water;
The treatment cost can be saved by 20% - 50%.
Polyaluminum sulfate liquid is prepared by adding 3% dilute sulfuric acid into ferrous sulfate, adding sodium nitrite and ferrous sulfate ratio of about 3:100, passing air or oxygen for oxidation, hydrolysis and polymerization.
The manufacturing methods of PFS solid products are as follows: 1. Liquid ferrous sulfate is used as raw material and Shengsheng air is used as oxidant. After low temperature dehydration, grinding, high temperature oxidation, xinxinran cooling, polymerization adjustment, solidification, aging and crushing, the finished product is finished.
Usage of polyferric sulfate
In use, the liquid PFS is usually mixed into 10% - 50% aqueous solution (which can be directly added when the source water has high turbidity), and the solid PFS is prepared into 10% - 30% aqueous solution. According to the specific situation, the prepared solution is put into the optimal conditions and dosage, and good coagulation effect can be obtained after full stirring.
The dosage can be determined according to the different turbidity of raw water. For general turbid water (turbidity is 100-500mg / L), 30-50kg of this product can be used per thousand tons. For non drinking water, high turbidity industrial sewage can be properly added.
In the treatment of industrial wastewater, the first grade PFS is diluted to 1-2 times of aqueous solution. When the concentration of source water is high and the amount of treated water is large, it can be directly added. Then according to the results of laboratory simulation test, according to the process conditions and dosage, after full stirring, coagulation and sedimentation, the clarified effluent can be obtained.
Precautions for use
1. Before use, put the product into the alum dissolving tank according to a certain concentration (10-30%), inject tap water and stir to make it fully hydrolyzed, and then put it to a reddish brown liquid, then dilute it with water to the required concentration and add coagulation. Water plants can also be mixed into 2-5% direct dosing, and industrial wastewater treatment can be directly mixed into 5-10% dosing.
2. According to the nature of raw water, it can be determined by production commissioning or beaker test depending on the amount of alum formation. The water treatment plant can use the original dosage of other chemicals as reference. Under the same conditions, the consumption of this product is roughly equivalent to that of solid polyaluminum chloride, which is 1 / 3-1 / 4 of that of solid aluminum sulfate. If the original liquid product is used, it can be calculated and determined according to the corresponding reagent concentration. It is roughly determined by the weight ratio of 1:3.
3. When in use, the prepared liquid medicine is pumped into the metering tank and coagulated with raw water through metering.
In general, it is necessary to use tap water for dispensing on the same day. It is normal to have a little sediment.
Precautions for storage of PFS:
Store in cool, dry and well ventilated warehouse. Keep away from fire and heat sources. The relative humidity was kept below 75%. The package must be sealed and protected from dampness.
It should be stored separately from inflammable (combustible), alkali, alcohol, etc., and should not be mixed storage. It should not be stored for a long time to avoid deterioration. The storage area should be equipped with suitable materials to contain the leakage.