O  ∥  R — C  \   O - ... H + ( Na + , K + ) is a weak acid, pKa = 4.7 ± 0.5 Table 1  Solubility product of various fatty acid salts (negative logarithmic value) Type of fatty acid Mg 2+ Ca 2+ Ba 2+ Ag + Cu 2+ Zn 2+ Cd 2+ Pb 2+ Mn 2+ Fe 2+ C 15 H 31 COO - 14.3 15.8 15.4 11.1 19.4 18.5 18.0 20.1 16.2 15.6 C 17 H 33 COO - 15.5 17.4 16.9 12.0 20.8 20.0 - 22.2 17.5 17.4 fatty acid Solubility in water fatty acid Solubility in water Tannic acid Undecanoic acid Lauric acid Tridecanoic acid Myristic acid 0.015 0.0039 0.0035 0.0035 0.0020 0.027 0.015 0.087 0.054 0.034 Pentadecanoic acid Palmitic acid Heptadecanoic acid 0.0012 0.00072 0.00042 0.00029 0.0020 0.0012 0.00081 0.00050 New Energy multifunctional air to water heat pump, all year round heating, cooling and domestic hot water supply solution. heating cooling heat pump,monobloc heat pump,cold climate heat pump Guangdong New Energy Technology Development Co., Ltd. , https://www.newenergy-e.com
Fatty acid collector, and can be an alkaline earth metal (Ca 2+, Mg 2+, Ba 2+) generated less soluble salts and heavy metal ions in Table 1.
     Collector longer hydrocarbon chains, is to increase the interaction between the main hydrocarbon chain, so that the collector capacity is increased, but often lack selectivity and therefore, the performance or floating mineral slurry pH range is widened.
For example, oleic acid, oxidized paraffin soap, tal oil, and naphthenic acid.
Carboxylic acid and its salts. Carboxylic acids, usually carboxylic acids are further divided into fatty acids and aromatic acids. In the flotation industry, fatty acids are important. Because fatty acids have very active shuttle group functionalities, almost all minerals can be floated, especially unsaturated acids, including oleic acid, linoleic acid, linolenic acid and ricinoleic acid. Wait. Compared with the corresponding saturated acid (such as stearic acid), these higher unsaturated acids have lower melting point, poor sensitivity to flotation temperature, large chemical activity, low freezing point and strong trapping performance. Therefore, high-level unsaturated acids and fatty acids and their sodium soaps are often used in the flotation industry.
Fatty acids and their salts are weak electrolytes that dissociate in water and their dissociation constant decreases as the hydrocarbon chain lengthens. The solubility of fatty acids in water is shown in Table 2 .
Table 2  Fatty acid solubility                   ( g .100g Water -1 )
Effect of length of fatty acid hydrocarbon chain on its capture performance: Studies on normal-saturated alkyl homologues show that within a certain range, the increase in the number of carbon atoms in the hydrocarbon chain will increase its trapping capacity, but the hydrocarbon chain If it is too long, the solubility of the agent is lowered, which results in poor dispersion in the slurry and lowers the collection performance.