-
摘要:
目前测定粉体接触角的方法主要有压片法和渗透法，但由于难以制得表面光滑的样品，因此压片法应用有很大的局限性。根据Washburn原理，通过测定液体在粉体柱内产生的压差随时间的变化计算不同药剂条件下石英的相对接触角。并结合单矿物浮选试验结果来判断相对接触角是否可以准确表征矿物表面润湿性。结果表明：不同药剂条件下石英回收率与测得的接触角呈正相关，相对接触角越大，回收率越高；在pH值为12、Ca2+浓度为3.75 mmol/L、油酸钠用量为2.81 mmol/L条件下，浮选效果最好。在此基础上，使用JK99C型全自动表面张力仪测定了不同条件下溶液的表面张力，计算了气泡与颗粒黏着单位面积前后自由能的变化，从热力学角度分析了与药剂作用后石英表面润湿性变化及其浮选行为发生变化的原因。
Abstract:The main methods to measure the contact angle of powders are pressing plate method and capillary penetration method. A commercial contact angle measuring instrument (JF99A) was applied according to Washburn technique to determine the relative contact angle of quartz under different reagent conditions by measuring the changes of the pressure difference over time produced by the liquid in the powder column. Combined with the flotation tests of quartz particles at the same concentrations, the relationship between their recovery and relative contact angle was analyzed, which proved that the relative wetting contact angle can characterize the surface wettability of quartz powders accurately. The flotation recovery was highest under the conditions of pH 12.0, Ca2+ concentration of 3.75 mmol/L and sodium oleate concentration of 2.81 mmol/L. Moreover, the surface tensions at different conditions were measured by a full-automatic tensiometer (JK99A). Under each condition, the free energy changes (ΔG) per unit area before and after the adhesion of bubble and particle were calculated respectively, which could illustrate the influences of reagents on flotation from the perspective of thermodynamics.
-
Key words:
- relative wetting contact angle /
- Washburn technique /
- free energy /
- flotation characteristics /
- sodium oleate /
- quartz
-
-
表 1 石英样品元素分析 /%
Table 1. Elemental analysis of quartz
成分 SiO2 Al2O3 Fe Mg 含量 99.5 0.33 < 0.001 < 0.001 
下载: 导出CSV
-
[1] 魏德洲.固体物料分选学:第三版[M].北京:冶金工业出版社, 2015:316.
[2] Smedley GT, Coles DE. A refractive tilting-plate technique for measurement of dynamic contact angles[J]. J Colloid Interface Sci, 2005, 286(1):310-8. doi: 10.1016/j.jcis.2005.01.090
[3] 徐志钮, 律方成, 赵鹏, 等.拟合方法用于硅橡胶静态接触角的测量[J].高电压技术, 2009(10):2475-2480. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=gdyjs200910026
[4] 徐志钮, 王国利, 赵丽娟, 等.亲水性时静态接触角算法及在硅橡胶憎水性检测中的应用[J].高电压技术, 2012(8):1891-1900. http://www.oalib.com/paper/4606843
[5] 徐志钮, 律方成, 张翰韬, 等.影响硅橡胶静态接触角测量结果的相关因素分析[J].高电压技术, 2012(1):147-156. http://www.cnki.com.cn/Article/CJFDTOTAL-GDYJ201201023.htm
[6] 丁晓峰, 管蓉, 陈沛智.接触角测量技术的最新进展[J].理化检验(物理分册), 2008, 44(2):84-89. http://mall.cnki.net/magazine/Article/LHJW200802010.htm
[7] 张世举, 程延海, 邢方方, 等.接触角与表面自由能的研究现状与展望[J].煤矿机械, 2011(10):8-10. doi: 10.3969/j.issn.1003-0794.2011.10.004
[8] 王晓东, 彭晓峰, 陆建峰, 等.接触角测试技术及粗糙表面上接触角的滞后性Ⅱ:粗糙不锈钢表面接触角的滞后性[J].应用基础与工程科学学报, 2003(3):296-303. http://www.cnki.com.cn/Article/CJFDTotal-HKDI200502009.htm
[9] Chau TT. A review of techniques for measurement of contact angles and their applicability on mineral surfaces[J]. Minerals Engineering, 2009, 22(3):213-219. doi: 10.1016/j.mineng.2008.07.009
[10] C.J Budziak, A.W Neumann. Automation of the capillary rise technique for measuring contact angles[J]. Colloids and Surfaces, 1990, 43:279-293. doi: 10.1016/0166-6622(90)80293-D
[11] Rodríguez-Valverde M A, Cabrerizo-Vílchez M A, Rosales-López P, et al. Contact angle measurements on two (wood and stone) non-ideal surfaces[J]. Colloids and Surfaces A:Physicochemical and Engineering Aspects, 2002, 206(1-3):485-495. doi: 10.1016/S0927-7757(02)00054-7
[12] Tomlison Fort Jr., H.T Patterson. A simple method for measuring solid-liquid contact angles[J]. Journal of Colloid Science, 1963, 18:217-222. doi: 10.1016/0095-8522(63)90013-8
[13] Anna Zdziennicka, Katarzyna Szymczyk, Joanna Krawczyk, et al. Some remarks on the solid surface tension determination from contact angle measurements[J]. Appl Surf Sci, 2017, 405:88-101. doi: 10.1016/j.apsusc.2017.01.068
[14] Kwok DY, Budziak CJ, Neumann AW. Measurements of static and low rate dynamic contact angles by means of an automated capillary rise technique[J].Journal of Colloid and Interface Science, 1995(1):143-150. http://cat.inist.fr/?aModele=afficheN&cpsidt=3583661
[15] C.W. Extrand, Sung In Moon. Measuring contact angles inside of capillary tubes with a tensiometer[J]. Journal of Colloid And Interface Science, 2014, 431. http://linkinghub.elsevier.com/retrieve/pii/S0021979714004512
[16] Atefi E, Mann A J, Tavana H. A robust polynomial fitting approach for contact angle measurements[J]. Langmuir, 2013, 29(19):5677-5688. doi: 10.1021/la4002972
[17] Washburn E. The dynamics of capillary flow[J]. Physics Review, 1921, 17(3):273-283. doi: 10.1103/PhysRev.17.273
[18] 陈国平, 陈邦林, 韩庆平.渗透压力法测定粉体接触角[J].大学化学, 1992(5):38-41. doi: 10.3866/PKU.DXHX19920509
[19] 韩德刚.化学动力学基础[M].北京:北京大学出版社, 1988.
[20] 王淀佐, 邱冠周, 胡岳华.资源加工学[M].北京:科学出版社, 2005:196-197.
[21] M C Fuerstenau, Jan D Miller, R E Pray. Metalion activation in xanthate flotation of quartz[J]. Transactions of the American Institutetute of Mining, 1965, 232:359-364. https://www.sciencedirect.com/science/article/abs/pii/S0301751616300503
[22] 王淀佐, 胡岳华.浮选溶液化学[M].长沙:湖南科学技术出版社, 1988:132-148.
[23] 寇珏, 郭玉, 孙体昌, 等.2种阴离子捕收剂在石英表面的吸附机理[J].中南大学学报(自然科学版), 2015, 46(11):4005-4014. doi: 10.11817/j.issn.1672-7207.2015.11.005
[24] 丘继存, 郭永文.多价金属阳离子对石英浮游的活化机理[J].有色金属(冶炼部分), 1965(7):35-43. http://mall.cnki.net/magazine/Article/METE196507009.htm
[25] 石云良, 邱冠周, 胡岳华, 等.石英浮选中的表面化学反应[J].矿冶工程, 2001, 21(3):43-45, 48. http://www.cnki.com.cn/Article/CJFDTOTAL-GNCL201315013.htm
-
图(8)
表(1)
计量
- 文章访问数: 1638
- PDF下载数: 24
- 施引文献: 0