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 European region struggled with the rising inflation that caused energy prices to rise leading to higher production costs thereby, negatively impacting the prices of titanium dioxide. The transportation routes were further disrupted along with the uncertainties in the construction and automotive industries. In addition to this, the offtakes and purchasing behaviour of the end-user consumers also declined, fueling the declining price trendss for titanium dioxide.

Abstract

The market for anatase titanium dioxide has expanded significantly over the years, driven by growing demand from various sectors. Manufacturers are now focusing on optimizing the production processes to enhance the quality and performance of anatase TiO2. This includes advancements in synthesis methods to produce nanoparticles with improved dispersion and stability. Companies are investing in research and development to innovate new applications, particularly in the fields of renewable energy and sustainable materials.

Très apprécié dans le travail des Icônes pour éclaircir, mais également pour les vernis, émaux, peintures, plastique et papier. A l'inverse, ne pas utiliser ce produit dans les applications cosmétiques, comme additif alimentaire ou comme additif médicamenteux.

Lithopone is chemically inert and practically insoluble in acids, alkalis and solvents. The optimized particle-size distribution of Lithopone attained by means of co-precipitation and calcining permit the achievement of a high apparent density, which imparts to Lithopone its low resin requirement and its excellent rheological behaviour.

EFSA’s scientific advice will be used by risk managers (the European Commission, Member States) to inform any decisions they take on possible regulatory actions.

≥30.0

But a chemical’s safety when it’s used externally is not always the same as when it’s ingested. Different uses of the same ingredient may cause very different health outcomes.

Lithopone

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.

0.5% Max

Permanence and Stability