Abstract：At present, methods of separating from low-grade barite ore are usually adopted to improve the grade of barite in flotation by using new flotation reagents, and the recovery of flotation can be improved by microwave pretreatment of the mineral before flotation, but the mechanism of microwave on flotation reagents and minerals are not yet known. In recent years, microwave heating technology has been used in mineral processing, metallurgy and material preparation and so on, with the advantage of fast reaction speed and high product index. In this paper, sodium oleate was used as a collector in the flotation tests of the pure barite mineral after microwave pretreatment, and the infrared spectrum detection was carried out for the barite flotation samples under different microwave heating times. The effect mechanism of microwave on barite flotation was discussed by the infrared spectral analysis of fitting smooth spectrum and second derivative spectrum. The flotation test results showed that the barite without microwave pretreatment had the best flotation index and recovery of 91.41% under the conditions of sodium oleate dosage of 55 mg·L-1 and pH value of 8.0. In contrast, the flotation index of barite treated with microwave increased gradually with the increase of microwave treatment time, and the recovery rate of barite treated with microwave in the 60 s was the highest, reaching 95.27%. Infrared spectrum analysis based on flotation test showed that in the flotation of barite without microwave pretreatment interacted with sodium oleate, the red shift of —CH2— symmetric stretching vibration peak at wavenumber 3 004 cm-1, —CH3 antisymmetric stretching vibration peak at wavenumber 2 953 cm-1, SO24 asymmetric stretching vibration peak at wavenumber 1 119 and 1 077 cm-1 were all found, indicating chemical adsorption of sodium oleate on the surface of barite was happened; By contrast, in the flotation of barite after microwave pretreatment interacted with sodium oleate, the red shift of —CH2— symmetric stretching vibration peak at wavenumber 2 853 cm-1, —CH2— symmetric stretching vibration peak at wavenumber 2 923 cm-1, —CH3 antisymmetric stretching vibration peak at wavenumber 2 958 cm-1, SO2-4 asymmetric stretching vibration peak at wavenumber 1 181，1 122 and 1 086 cm-1, SO2-4 symmetric stretching vibration peak at wavenumber 982 cm-1, SO2-4 bending vibration peak at wavenumber 635 and 610 cm-1 were not found, but the peak strength increased significantly with the microwave heating time, and the peak strength increased most significantly with the microwave heating time of 60 s. The fitting smoothing spectrum and the second derivative spectrum calculations of the infrared spectrum after microwave pretreatment showed that the peak area at wavenumber 2 958，2 923，2 853，1 181，1 122，1 086，982，635 and 610 cm-1 increased to different degrees, and under microwave heating 60 s, the peak area respectively increased by 1.84%, 259.12%, 761.15%, 235.72%, 145.61%, 198.50%, 641.16%, 549.67% and 744.97%. It indicates that microwave pretreatment does not induce a chemical reaction on the barite surface, but strengthens the chemical adsorption between sodium oleate collector and barite ore, make the chemical adsorption on the barite surface denser, and the adsorption quantity increased, so the barite recovery increases and the flotation index improves.
Key words：FTIR; Microwave; Barite; Fit smooth spectrum; Second derivative spectrum
武靖轩，李 解，林嘉威，弋诗文，李 敏，苏文柔. 红外拟合光谱分析微波对重晶石浮选的影响机理[J]. 光谱学与光谱分析, 2021, 41(10): 3083-3091.
WU Jing-xuan, LI Jie, LIN Jia-wei, YI Shi-wen, LI Min, SU Wen-rou. Influence Mechanism of Microwave on Barite Flotation Based on Infrared Fitting Spectrum Analysis. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2021, 41(10): 3083-3091.
[1] LI Chuan-chang，ZHANG Wen-rui，TANG Ai-dong（李传常，张文睿，唐爱东）. Study on Occurrence of Barite of Ore Tailing(尾矿中重晶石赋存状态的研究). 6th Annual Conference of Chinese Society of Particuology cum Symposium on Particle Technology across Taiwan Straits（中国颗粒学会第六届学术年会暨海峡两岸颗粒技术研讨会），2008. 225.
[2] Kingman S W，Jackson K，Bradshaw S M. Powder Technology，2004，146 (3)：176.
[3] WANG Dian-zuo，HU Yue-hua(王淀佐，胡岳华). Solution Chemitry of Flotation（浮选溶液化学）. Changsha：Hunan Scienceand Technology Press（长沙：湖南科学技术出版社）, 1988. 1.
[4] MENG Qing-you，YUAN Zhi-tao，MA Long-qiu，et al（孟庆有，袁致涛，马龙秋，等）. Journal of Northeastern University·Natural Science Edition（东北大学学报·自然科学版），2018，39(4)：599.
[5] Znamenackova I, Lovas M, Hredzak S, et al. An Application of Microwave Heating in Treatment of Selected Minerals Geo Comference on Science and Technologies in Geology, Exploration and Mining, Sgem 2014，Vol. Ⅲ，2014，965.
[6] da Silva G R, Waters K E. Advanced Powder Technology，2018, 29: 3049.
[7] ZHANG Bo，LI Jie，ZHANG Xue-feng，et al（张 波，李 解，张雪峰，等）. Chinese Journal of Rare Metals（稀有金属），2016，40(9)：963.
[8] WENG Shi-fu，XU Yi-zhuang（翁诗甫，徐怡庄）. Fourier Transform Infrared Spectrum Analysis（傅里叶变换红外光谱分析）. Beijing：Chemical Industry Press（北京：化学工业出版社），2016.
[9] QI Zong, SUN Chuan-yao（祁 宗，孙传尧）. Journal of China University of Mining & Technology（中国矿业大学学报），2013，42(3)：461.
[10] Zheng R J，Ren Z J，Gao H M，et al. Minerals，2018，8(2): 57.
[11] XU Peng-yun，LI Jing，CHEN Zhou，et al（许鹏云，李 晶，陈 洲，等）. Spectroscopy and Spectral Analysis(光谱学与光谱分析)，2017，37(8)：2389.
