What is the distributive law of extraction?

A unit operation that uses the different solubility of the components in the system in the solvent to separate the mixture; Take advantage of the difference in solubility or partition coefficient of a substance in two immiscible (or slightly soluble) solventsTransfers a substance from one solvent to another. After repeated extractions, most of the compounds were extracted.

The solvent extraction process generally consists of extraction, washing, and reverse extraction. Generally, the process of extracting solutes from the aqueous phase is called extraction, the process of removing other solutes or inclusions from the loaded organic phase in the aqueous phase is called scrubbing, and the process of resolving solutes in the organic phase from the aqueous phase is called stripping.

Extraction principle. The law of partition is the main basis for the theory of extraction method, and substances have different solubility to different solvents. At the same time, when a soluble substance is added to two immiscible solvents, it can be dissolved in the two solvents respectively;

Experiments show that at a certain temperature, the ratio of the compound in the two liquid layers is a fixed value when there is no decomposition, electrolysis, association and solvation of the two solvents. Regardless of the amount of substance added, it is a physical change. Expressed in formulas.

The Law of Arithmetic and Simple Calculations:

Commutative law of addition: a+b=b+a

Two additions swap positions, and the sum is invariant, which is called the commutative law of addition.

2.additive associative law; （a+b）+c=a+（b+c）

Adding the first two numbers first or adding the last two numbers first, and the sum is unchanged, which is called the law of addition and associativity.

3.Commutative law of multiplication: a b = b a

Swap the positions of two factors, and the product is invariant, which is called the multiplicative commutative law.

4.Multiplicative associativity: (a b) c = a (b c) or a b c = a (b c).

Multiplying the first two numbers or the last two numbers first, and the product remains the same, which is called the associative law of multiplication.

5.Multiplicative distributive property: (a+b) c=a c+b c or (a-b) c=a c-b c

Inverse application of the multiplicative distributive property: a c + a b = (a + b) c or a c - b c = (a-b) c

When the sum of two numbers is multiplied by a number, they can be multiplied separately by the number and then added, which is called the multiplicative distributive law.

6.In a mixture of addition and subtraction, it is possible to swap the positions of subtraction and addition. However, it is necessary to "move" together with the previous operator symbol when swapping places, and the result of the operation will not change.

i.e.: a-(b-c)=a-b+c; a-（b+c）=a-b-c

7.In a hybrid operation of multiplication and division, the order of multiplication and division operations can be exchanged, and the result of the operation does not change. However, it is necessary to "move" together with the previous operator symbols when swapping places.

i.e.: a b c = a (b c)=a c b; a÷b×c=a÷（b÷c）

Note: The reason for the introduction of the apparent partition coefficient was the "measurement problem". In the aqueous phase, only the sum of [green cooh] and [green c00*] can be measured. So to convert it.

ko = [green cooh] [green cooh] down, [green cooh] upper = ko [green cooh] lower (1).

kp = ( cyan c00] down [h+]) [cyan co0h] down [cyan c00] down = kp [cyan cooh] p [h+].

k = [green cooh] ( [green co0h] down + [green c00]) substitute (1) and (2) into (3).

k = ko [green coqh] lower ([green coqh] lower + kp[green coqh]t [h+].

k= ko[h+] / （kp + h+])