Research On The Combustion Method To Determine The Quantity Of Fatty Acid Collector Adsorbed On Minerals

The measurement of the adsorption of flotation reagent on mineralsurfaces is of great significance to the understanding of the function of thereagent. However, it is difficult to assay the collector adsorbed on mineralsurfaces. In this thesis, a new combustion method, with constant volume andoxygen circulation, was investigated to quantitatively determine fatty acidcollector adsorbed on minerals. This method is based on the analysis of thecarbon dioxide quantity produced from burning the sample with fatty acidcollector adsorbed on its surface under a suitable temperature, thus theadsorption of collector on mineral surface is indirectly measured.Themethod was proved to be practical, easy to realize, and of value to bothflotation research and flotation production.Through numerous experiments and improvements, fundamentalfactors and conditions which influence the determination and theapplicability of the method were established. From a series experiments onmethods to determine the CO₂gas concentration produced from thecombustion, including the chemical—absorption titration method, theNDIR1instrumental method and the continuous flow NDIR method, thebest method was determined to be the constant volume-oxygen recirculationNDIR method. The measurement accuracy increased, and the workefficiency enhanced using this method. Using sodium oleate as a standardflotation collector in this thesis, the lowest combustion temperature wasdetermined to be400℃; the lowest catalytic reaction temperature wasdetermined to be600℃. Under the experimental conditions determined, agood linear relationship exists between the amount of sodium oleate burnt and the CO₂it produced, indicating this method can be used toquantitatively analyze sodium oleate collector adsorbed on mineral surfaces.Comparison between the combustion method and the traditionalsolvent extraction-spectrophotometric method to determine sodium oleateadsorbed on mineral surfaces showed that the traditional solventextraction-spectrophotometric method has disadvantages such as the usingof volatile，toxic extracion solvent （Chloroform） which was harmful toanalyst and hard to handle the used solvent, and the high cost of analysisMoreover, in the actual measuring process, the grinding fineness of thesample usually has a great influence on the accuracy of analytical the results.In comparison, the constant volume—oxygen circulation combustionmethod is simpler and practical, convenient to operate, less time-consuming,low-cost, more environmentally friendly, repeatable, and more accurate.After the establishment of the combustion method as a method todetermine fatty acid collector, the possible application of this method inflotation research was also discussed in this thesis. The adsorption ofcollector under the actual phosphate flotation conditions were measuredusing the above method. Once again, those results proved that thecombustion method to determine fatty acid collector adsorption on mineralsurfaces is practical and easy to realize. A good positive correlation existsbetween the adsorption quantity of collector and the flotation of a phosphateore.