First, the effect of temperature on activity and activity coefficient The commonly given activity coefficient is the value at 25 ° C (298 K). For other activity coefficients, Meissner proposes the following equation to correct the q o value. Where Δt = t-25; the values ​​of a and b are -0.0079 and -0.0029 for sulfates, and -0.005 and -0.0085 for other electrolytes. Furthermore, the value of Г in equation (2) must be changed to correct the Debye-Cocker parameter containing the temperature-dependent variable D. Second, the effect of complexes on activity and activity coefficient (1) Formation of complexes The deviation of the Debye-Shocker's extreme law for strong electrolyte slags with concentrations greater than 10 -3 mol∕L indicates that in these solutions, the electrostatic attraction between ions no longer dominates the G ex value. In various attempts to extend the Debye-Hickel's extreme law, although short-range effects are considered in different ways, they all assume that no chemical bonds are formed by electron interaction between ions, and no new substances are formed. Since there is currently no way to calculate the effect of such inter-electron interactions on the G ex value, this assumption can only be made. For the new compounds formed between the components in the solution, whether between ions and ions or between ions and neutral molecules, the free energy of formation cannot be calculated. Such reactions for the chemical and hydrometallurgical processes are very important, in order to deal with these reactions, and wet chemical processes metallurgist from another angle, namely by a chemical equilibrium treated to obtain experimentally measured Balance constants to quantify them. Consider a z+ valence metal ion M z + in a solution containing a monovalent anion L − . When they act, it is assumed that L - is a ligand and the product is called a complex. The complex is formed hierarchically, and each stage is controlled by an equilibrium constant: The maximum number n of L - ions forming a complex with M z + is called the coordination number of M z + . The total equilibrium constant β (called the instability constant) is General form, cumulative instability constant β n = K 1 K 2 K 3 ... Kn If the ligand is an uncharged molecule, such as ammonia, and the equilibrium is treated in the same manner, the charge number of each complex is z+. The factors controlling the absolute and relative amounts of each metal-containing component and free ligand in the solution are: 1. The value of all equilibrium constants; 2. Total concentration of all forms of metal [M t ]; 3. Total ligand concentration [Lt]; 4. The ratio of the above two concentrations; 5. The activity coefficient of each component involved in the balance. In the case where the total metal concentration in the dispersion is constant, as the total ligand concentration increases from zero, the complex ML is formed first and its concentration gradually increases, and begins to decrease when the complex ML 2 is produced. The concentration of the complex ML 2 is also gradually increased, and is decreased again when a higher-order complex is formed. The degree of formation of the complex MLm is defined by: α MLm = [ML m ] / [M t ] However, if a multinuclear complex is present, it contains more than one metal atom per ion or molecule, and the concentration is multiplied by the number of metal atoms contained in the calculation. The average number of ligands is defined as That is, the concentration of the ligand bound in the complex divided by the total concentration of the metal, which is especially important when measuring the equilibrium constant. When writing about a balanced chemical equation, solvation of the substances involved in the equilibrium is usually ignored. In fact, in aqueous solution, metal ions are strongly hydrated, and in many cases the ligand is considered to be a water molecule at a coordination position around the metal atom. For example, the Cu(NH 3 ) 4 2 + ion contains four amino groups arranged at four corners of a square centered on a copper atom. An amino group can be considered to replace a water molecule in the same position. Like all other divalent and trivalent metal ions in the first transition series in the periodic table, the simple hydrated Cu 2 + ion has six coordinating water molecules arranged at the apex of the octahedron. However, due to the Jahn-Teller effect, the octahedron of Cu 2 + ions is distorted, so the metal ions are weakly combined with the fifth and sixth ligands, including hydrated water molecules. Therefore, the stepwise equilibrium constant (25 ° C) in the ammine is lgK 1 lgK 2 lgK 3 lgK 4 lgK 5 4.15 3.50 2.89 2.13 -0.52 The Cu(NH 3 ) 5 2 + ion can be formed in a very concentrated aqueous ammonia solution, and the sixth ammonia molecule can only be combined in liquid ammonia. Buyron explains why the K value decreases with the increase in the number of NH 3 groups bound to the Cu 2 + ions. He refers to the logarithm of the ratio of two adjacent equilibrium constants as the total effect, T (m -1 ), m and divides it into statistical effects S (m -1 ), m and ligand effect L (m -1 ), m two quantities. The tendency of the ligand L to be lost from the component ML m is proportional to the value of m, while the tendency of the component ML m in combination with the other ligand group L is proportional to the value of (n-m). The ratio of n consecutive stable constants will be The ratio of two consecutive stable constants caused by statistical reasons alone is therefore This equation can be applied when each coordinating group occupies only one coordination position and the n coordination positions around the metal ion are identical. The first four constant K values ​​of the Cu II -NH 3 system are on the same order of magnitude, and the correction values ​​are adjusted in consideration of statistical factors, which are more evenly close: lgK 1 (corr), 3.55 lgK 2 (corr), 3.32 lgK 3 (corr), 3.07 lgK 4 (corr), 2.73 Therefore, the difference between the test values ​​can be mainly attributed to the statistical effect. Buyron divides the ligand effect itself into electrostatic effects and static effects. The electrostatic effect is caused by the charge between the ligand and the metal-containing component. The ligand ion L - is attracted to M 2 + or ML + but is repelled from ML 3 - . Buyron derived an equation to calculate the value of the electrostatic effect, and given the uncertainty of use, the static effect is only considered for uncharged ligands. Certain types of ligands can occupy two coordination positions, which is a bidentate ligand. For example, ethylenediamine (en), H 2 N·CH 2 ·CH 2 ·H 2 N, carbonate, and many organic substances containing a neutral coordinating group and an acidic group, such as glycine, H 2 N· CH 2 ·COOH. It can be attached to a metal ion by its acid group, neutralizing a positive charge, or it can form a covalent bond with a metal by a nitrogen atom to form a chelate. A Jaw Crusher is one of the main types of primary crushers in a mine or ore processing plant. The size of a jaw crusher is designated by the rectangular or square opening at the top of the jaws (feed opening). Primary jaw crushers are typically of the square opening design, and secondary jaw crushers are of the rectangular opening design. 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(1) (2) =([L t ]-[L])/[M t ]
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