Basic principle of hydrolysis process and digital model control

Antimony trioxide hydrolysis at higher acidity, while the other metal ions hydrolyzed low acidity, i.e. high pH. Therefore, the hydrolysis process of antimony trichloride is an excellent impurity removal process.

The volume of the antimony trichloride stock solution and the hydrolyzate are V _original and V _{T respectively} ; the total antimony, total chlorine and other metal ion concentrations in the antimony trichloride stock solution and hydrolyzate are [Sb ^{3 +} ] _{T original} , [Cl ^- ] _{T- origin} , [Me ^{n +} ] _{T- origin} and [Sb ^{3 +} ] _T , [Cl ^- ] _T and [Me ^{n +} ] _T , the hydrolyzate acidity is [H ⁺ ], and the hydrolyzate is Sb ₄ O ₅ Cl ₂ . A series of formulas for calculating the amount of water added or the neutralizing dose can be derived from the basic thermodynamic model of the antimony trioxide hydrolysis system, formula (1) and (2), to control the hydrolysis process in a flexible manner. Only some representative and common formulas are introduced here. For example, the dilute hydrolysis of a pure ruthenium trichloride solution is carried out in a Sb(III)-Cl ^- -H ₂ O hydrolysis system, and therefore, B = 0.

(1)

(2)

The amount of water added (dm ³ ) calculated as the concentration of hydrolyzate is:

(3)

The dilute hydrolysis of pure solid antimony trichloride is:

(4)

The weight of G-solid antimony trichloride in the formula, g.

The dilute hydrolysis of a ruthenium trichloride solution containing other metal ions which do not form a chlorine complex ion is carried out in the Sb(III)-Me(I)-Cl ^- -H ₂ O hydrolysis system, and is calculated according to the hydrolysis rate:

(5)

For the neutralization and hydrolysis of the antimony trichloride solution with an alkali solution as a neutralizing agent, the amount of the alkali solution can be calculated according to the formula (6):

(6)

In the formula, V _base and [Me ⁺ ] _base - represent the volume and concentration of the lye.

When using an alkali metal salt or oxide which does not form a chlorine complex anion as a neutralizing agent, there are:

(7)

Wherein, G, N _is the number of grams and the gram equivalent of the neutralizing agent, respectively. When a basic compound of zinc capable of forming a chlorine complex ion is used as a neutralizing agent, the hydrolysis process is carried out in the Sh(III)-Zn(II)-Cl ^- -H ₂ O system, in which case:

(8)