煤气化细渣作为煤气化过程中所产生的固废资源，将其中碳灰有效分离是实现煤气化细渣高效资源化利用的首要前提。本文以关中某煤化工厂的水煤浆气化细渣为研究对象，选用非极性烃类油十二烷分别与极性药剂十二醇、十二酸、十二胺进行复配，通过浮选方法实现碳灰分离，并结合浮选产品的精尾矿物理化学性质差异，探究复配捕收剂对煤气化细渣碳灰浮选分离结果的影响；借助接触角分析、红外分析、Zeta电位测定以及低场固体核磁等分析检测方法来表征复配药剂在煤气化细渣表面的吸附作用机理。

研究了煤气化细渣的基本性质。煤气化细渣样品的灰分为53.60%，小于0.045 mm的粒级为主导粒级，产率和灰分分别为37.76%和75.69%，表明该样品中高灰细粒物料含量较大。样品中主要含有石英、莫来石以及硬石膏等亲水性矿物，无机矿物质主要以非晶相存在的SiO₂及Al₂O₃为主。

探究了不同药剂种类、药剂配比、药剂用量对煤气化细渣浮选结果的影响。复配捕收剂浮选结果优于十二烷单独作捕收剂，且十二烷与十二胺复配作捕收剂，复配体积比为40%，药剂用量为15 kg/t时浮选效果最佳。此时，捕收剂可燃体回收率为90.82%，精矿灰分为34.45%，尾矿灰分为87.43%，浮选完善指标为47.83%；相较于同一药剂用量下十二烷的浮选结果，可燃体回收率提高了29.50%，尾矿灰分增大了20.47%，浮选完善指标提高了14.74%，但无论改变药剂种类或药剂配比，精矿灰分与十二烷单独作用基本一致。通过对浮选产品分别进行物理化学性质分析，从宏观角度讲，该煤气化细渣样品高灰细粒物料含量较高，一部分细粒级无机质容易夹杂在泡沫中随精矿浮出，从而导致精矿灰分居高不下；从微观角度讲，由于煤气化细渣浮选入料及浮选精矿较大的比表面积以及复杂的孔隙结构，使含Si、Al元素的微细粒球形无机灰质经分选过后仍填充于未燃炭孔结构内，因此使得精矿灰分仍居于30%左右难以降低。

揭示了复配捕收剂在煤气化细渣表面的吸附作用机理。极性药剂十二醇、十二酸、十二胺分别与十二烷复配后，油滴在水中具有良好的分散性，显著提高了煤气化细渣表面含量官能团的被覆盖率，从而有效提高煤气化细渣表面的疏水性。捕收剂经复配后疏水端以疏水作用定向吸附在煤气化细渣表面疏水位点，极性基团以氢键作用吸附在煤气化细渣表面含氧位点，极性基团与非极性基团共同作用于煤气化细渣表面以提高浮选性能；对比非极性药剂十二烷、极性药剂十二醇及十二烷-十二醇复配捕收剂三种药剂在煤气化细渣表面的低场核磁信号，极性与非极性药剂的复配，一定程度上减小了浮选药剂在煤气化细渣孔隙中的无效吸附，从而达到有效减少捕收剂用量的目的。

As a solid waste resource generated during the process of coal gasification, efficient utilization of the coal gasification fine slag (CGFS) requires effective separation of carbon ash, which is the primary prerequisite. Taking the coal-water slurry gasification fine slag from a coal chemical plant in Guanzhong as the research object, non-polar hydrocarbon oil dodecane was selected to be composited with polar reagents including dodecanol, lauric acid, and lauryl amine respectively. The flotation method was employed to achieve carbon ash separation. Combined with differences in physical and chemical properties of refined tailings from flotation products, this study explored the influence of compound collectors on flotation separation of carbon ash from CGFS. The adsorption mechanism of composite collector on the surface of CGFS was characterized through contact angle analysis, infrared analysis, Zeta potential determination, and low-field solid nuclear magnetic resonance.

The basic properties of CGFS were studied. The ash content of CGFS sample was 53.60%, and the particle size less than 0.045 mm was the dominant particle size. The yield and ash content were 37.76% and 75.69%, respectively, indicating that the content of high ash fine material in the sample was large. The sample mainly contained hydrophilic minerals such as quartz, mullite and anhydrite, and inorganic minerals mainly consisted of SiO₂ and Al₂O₃ in amorphous phase. 

The influence of different reagent types, reagent ratio and reagent dosage on the flotation results of CGFS was explored. The flotation results of composite collector are better than dodecane alone as collector, and dodecane and lauryl amine are composited as collector, the volume ratio of composite is 40%, and the dosage of reagent is 15 kg/t, the flotation effect is the best. At this time, the combustible recovery is 90.82%, the concentrate ash content is 34.45%, the tailings ash content is 87.43%, and the flotation perfection index is 47.83%. Compared with the flotation results of dodecane with the same dosage of reagent, the combustible recovery is increased by 29.50%, the ash content of tailings is increased by 20.47%, and the flotation perfection index is increased by 14.74%, but no matter how to change the type or proportion of reagents, the ash content of concentrate is basically the same as that of dodecane. Through the physical and chemical properties analysis of the flotation products,from the macro point of view,the CGFS sample has a high content of high ash fine particles,and some fine grained inorganic matter is easy to be mixed in the foam with the flotation of the concentrate, resulting in high ash content of the concentrate. From the micro point of view, due to the large specific surface area of the CGFS flotation feed and the complex pore structure of the flotation concentrate, the fine spherical inorganic ash containing Si and Al elements is still filled in the unburned carbon pore structure after separation, so that the ash content of the concentrate is still difficult to reduce to about 30%.

The adsorption mechanism of composite collector on the surface of CGFS was revealed. When the polar agents dodecanol, lauric acid, and lauryl amine are mixed with dodecane respectively, the oil droplets have good dispersibility in water, and the coverage of functional groups on the surface content of CGFS is significantly increased, thus effectively improving the surface hydrophobicity of CGFS. The hydrophobic carbon chain of the collector is directively adsorbed to the hydrophobic water level point on the surface of the CGFS by hydrophobic action. The polar groups are mainly adsorbed to the oxygen-containing site on the surface of the CGFS by hydrogen bonding, and interact with the non-polar groups on the surface of the CGFS to improve the flotation performance. By comparing the low field nuclear magnetic signals of dodecane, dodecanol and dodecane-dodecanol compound collector on the surface of CGFS, the combination of polar and non-polar agents can reduce the ineffective adsorption of flotation agents in the pores of CGFS to a certain extent, so as to effectively reduce the amount of collector.

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