2: Clarification mechanism of coagulant
Chemical coagulation is a process in which chemical agents (coagulants) are added to water treatment to make colloidal dispersion system destabilize and agglomerate. In the coagulation process, small suspended particles and colloidal impurities are aggregated into larger solid particles to separate particulate impurities from water, which is called coagulation clarification.
After adding coagulant into water, colloidal particles and other small particles can be polymerized into larger flocs through the comprehensive action of mixing, coagulation and flocculation. The whole process of coagulation and flocculation is called coagulation.
(1) Destabilization and condensation of colloids
Adding electrolyte to water can compress the electric double layer and destabilize the colloid. The main mechanism is that the electric double layer of colloidal particles in water is compressed or neutralized by adding aluminum salt or iron salt coagulant. The coagulant and raw water are mixed rapidly and evenly, and a series of chemical reactions are produced to destabilize. This process takes a short time, generally about 1 min. Some cationic polymers can also play a role in the destabilization and condensation of colloids in water. These polymers have a long chain structure and positive charge in water. Their destabilization and condensation of colloids in water is due to the interaction of van der Waals force adsorption and electrostatic attraction.
(2) Flocculation and formation of floc (alum)
The particle size of the initial flocculate formed by colloid destabilization and coagulation in water is generally more than 1 m. at this time, Brownian motion can no longer push them to collide and form larger particles. In order to make the initial flocs collide with each other to form large flocs, it is necessary to input additional energy into the water to produce a velocity gradient. Sometimes it is necessary to add organic polymer flocculant into water, and the adsorption bridging effect of long chain molecules of flocculant is used to improve the probability of collision and adhesion. Flocculation efficiency usually increases with the increase of flocculate concentration and flocculation time.
Compared with polyaluminum chloride, polyaluminum chloride has the advantages of high density, fast settling speed and wide pH adaptability; the coagulation effect is less affected by temperature than that of polyaluminum sulfate; however, when adding ferric salt, it should be noted that when the equipment is not in normal operation, the iron ions will make the effluent color, and may pollute the subsequent desalination equipment.
The global Lithopone market was valued at $169.8 million in 2019, and is projected to reach $218.6 million by 2027, growing at a CAGR of 3.30% from 2020 to 2027.
The titanium dioxide helps to protect the Ponceau 4R from external factors such as heat and light, while also providing a white base that gives the colorant a more vibrant and appealing appearance The titanium dioxide helps to protect the Ponceau 4R from external factors such as heat and light, while also providing a white base that gives the colorant a more vibrant and appealing appearanceponceau 4r and titanium dioxide manufacturer.The R996 grade titanium dioxide from Lomon is particularly well-suited for use in the paint industry due to its superior tinting strength and dispersibility. These properties allow paint manufacturers to achieve vibrant and consistent colors in their products, resulting in high-quality finishes for a variety of applications.
Lithopone was discovered in the 1870s by DuPont. It was manufactured by Krebs Pigments and Chemical Company and other companies. The material came in different seals, which varied in the content of zinc sulfide. Gold seal and Bronze seals contain 40-50% zinc sulfide, offering more hiding power and strength. Although its popularity peaked around 1920, approximately 223,352 tons were produced in 1990. It is mainly used in paints, putty, and in plastics.
They serve as cost-effective alternatives to titanium dioxide, another widely used white pigment, while offering comparable performance qualities They serve as cost-effective alternatives to titanium dioxide, another widely used white pigment, while offering comparable performance qualitieslithopone pigments manufacturer.