Zirconium Carbonate_Industrial Additive

Zirconium Carbonate [Background and Overview]

Zirconium sulfate and zirconium carbonate are two distinctive products in the zirconium compound series. Zirconium sulfate is mainly used to prepare tanning agents for leather products, decolorizing agents in the pharmaceutical industry, paint stabilizers, fiber treatment agents and intermediates of other zirconium compounds. Zirconium carbonate is the basic raw material for preparing zirconium salts. It is widely used in high-tech fields such as functional ceramics, structural ceramics, automobile exhaust gas treatment, light storage materials, leather, papermaking, cosmetics, and paint driers. It is also the most popular method for producing ultrafine zirconium dioxide. Economical production raw materials.

Zirconium carbonate is an inorganic compound with a chemical formula of CH₄O₁₀Zr₃, a molecular weight of 449.70800, and a logP of -0.84420. PSA is 144.10, melting point is 135°C (dec.)(lit.). Zirconium carbonate is a white powdery solid that is soluble in ammonium carbonate and easily soluble in organic acids to form the corresponding organic acid zirconium, which is more easily soluble in inorganic acids but insoluble in water and organic solvents. It is easy to decompose when heated, so it is not suitable for long-term storage. Zirconium carbonate can be converted into zirconium oxide by high-temperature calcination. The composition of zirconium carbonate is also very complex. Its composition mainly depends on the difference in the process used, especially the “step-by-step liquid precipitation method” process. The composition of the intermediate used – zirconium sulfate is the basic structure of zirconium carbonate. Zirconium and carbonate can form a series of compounds, and basic zirconium carbonate is a commonly used product in industry. The data reported are: Zr₂O₃(OH)₂CO₂·nH₂O, ZrO₂·CO₂· nH₂O, Zr(OH)₂CO₂·nH₂O, ZrOCO₃·nH₂O. A more appropriate expression of the molecular formula can be: 2ZrO₂·CO₂·nH₂O. Due to different preparation methods and process conditions, the molar ratio of zirconium dioxide and carbon dioxide in the molecule varies between 4:1 and 1:1. Basic zirconium carbonate reacts with sodium or ammonium carbonate to form soluble double salts, such as NH₄[Zr(OH)₃(CO₃)₃] etc. CO32-:Zr= 1.5, 2.5, 3.0, 3.5 or 4:1 in the double salt molecule.

Zirconium Carbonate [Synthesis]

1. One-step process production: Zirconium carbonate can be produced by direct reaction of salts such as sodium carbonate or ammonium carbonate and zirconium solution. Products produced by reaction in aqueous solution have low zirconia content and low purity; products of better quality can be obtained by reaction in organic solution. Domestic manufacturers of zirconium carbonate mainly use a one-step process. The principle is: zirconium oxychloride solution and sodium sulfate solution react to form sodium zirconium sulfate double salt, which is then reacted with sodium bicarbonate to produce zirconium carbonate. Because of these two reactions All are carried out in a reaction device, so it is called “one-step method”.

2. Step-by-step liquid phase precipitation method: Using a special reaction device, zirconium oxychloride solution reacts with sulfuric acid (or sulfate) to generate basic zirconium sulfate, and sulfuric acid and catalyst KA01 are added through directional diversion and temperature control adjustment. As a result, the morphology of basic zirconium sulfate can be better controlled, and the activity of zirconium carbonate can be controlled. The zirconium carbonate generated in this way has a high CO₂ content, and the particle size D50 reaches the range of 25 to 50 μm, which is higher than that of zirconium carbonate. The surface area is controlled at 1 to 2 m²/g, the recovery rate is stable at around 98%, and the product activity is significantly improved, so it is also called highly active zirconium carbonate. Highly active zirconium carbonate produced by the “step-by-step liquid phase precipitation method” process, product development involves key technologies such as basic zirconium sulfate crystal formation and growth conditions, transformation, catalytic theory and catalytic mechanism, catalyst selection technology, design of special reaction system, etc. . The step-by-step liquid phase precipitation process is: first make zirconium oxychloride into a methoxyphenylboronic acid solution, then introduce a certain amount of sulfuric acid or sulfate and catalyst KA01 in proportion. After the addition, control the stirring speed and heat the system to a certain temperature, after maintaining the system temperature for a period of time, take a sample and observe its morphological structure with a microscope. Stop the reaction after reaching the standard, wash the precipitate with deionized water, and then react the washed basic zirconium sulfate with carbonate at normal temperature and pressure, that is Can produce zirconium carbonate. This process has the characteristics of low investment, short process, high recovery rate, and low cost. The high-quality zirconium carbonate produced by this process has strong market competitiveness in the international market.

Zirconium carbonate [Application]

Zirconium carbide is a hard, high-melting-point material and an excellent high-temperature refractory material. A raw material used as solid propellant in rocket engines. Used in the production of alloy steel. It is also the raw material for the production of zirconium salts, metallic zirconium and zirconium tetrachloride, which are widely used in high-tech fields such as functional ceramics, structural ceramics, automobile exhaust treatment, light storage materials, leather, papermaking, cosmetics, and paint driers. Oxypyridine fine zirconium dioxide is the most economical production raw material and is a promising fine ceramic material. Application examples are as follows:

An environmentally friendly method for preparing zirconium oxide colloid uses zirconium carbonate and strong inorganic acid as raw materials to prepare zirconium oxide colloid with stable properties and wide solid content distribution. Dissolve zirconium carbonate in an appropriate amount of strong inorganic acid and stir evenly quickly. At this time, zirconium carbonate decomposes under the action of strong acid. The decomposed product forms a transparent solution in the acidic solution. The solution is then placed under constant temperature conditions. Concentrate to obtain zirconia colloid with a solid phase weight content of 20% to 55%. Among the above technical solutions��The molar ratio of the raw material zirconium carbonate and hydrochloric acid or nitric acid used is Zr⁴⁺:Cl-=0.8~1.3:1 or Zr⁴⁺:NO^3-=0.8~1.3:1. In the above technical solution, the selection range of the constant temperature and concentration temperature is 10 to 90°C.

The technical solution includes the following steps:

a. Calculation of raw material dosage: According to the molar ratio of zirconium carbonate to hydrochloric acid or nitric acid Zr⁴⁺: Cl^–=0.8~1.3:1 or Zr^{4 +}:NO^3-=0.8~1.3:1, weigh zirconium carbonate and hydrochloric acid or nitric acid respectively;

b. Solution preparation: slowly add the proportion of hydrochloric acid or nitric acid to the weighed zirconium carbonate under vigorous stirring, and continue stirring until the zirconium carbonate dissolves to obtain a transparent solution;

c. Place the prepared transparent solution in a constant temperature of 10 to 90°C and concentrate to obtain a zirconia colloid with a solid phase content of 20% to 55%. The molar ratio of the above-mentioned zirconium carbonate and hydrochloric acid or nitric acid is preferably Zr⁴⁺:Cl^–=1:1.1～1.2 or Zr⁴⁺: NO^3-=1:1.1～1.2. The temperature of the above constant temperature concentration is preferably 20 to 60°C. The above constant temperature concentration time is preferably 1-2 hours.

Zirconium carbonate [Reference]

[1] Luo Fangcheng, Lu Wenguang, Luo Xinwen. A review of the properties, applications and production technology of zirconium sulfate and zirconium carbonate [J]. Rare Metals, 2003, 27(1): 53-56.

[2] Li Xianxiang. A preparation method of zirconium oxide colloid. CN201010533156.8, application date 2010-11-05