Synthesis of Super Plasticizer NF-30 from Coal Coking by Product Washing Oil and Performance Analysis

Super plasticizer was synthesized by using coal coking by product washing oil and industrial naphthalene. The results show that sulfonationt time （2.5 h）, sulfonation temperature （160 ℃） and condensation time （5.0 h） are key factors. Adding oxidizing agent MO in the course of synthesis can decrease the emission of SO2 in exhaust （20%）. Compared with NF, NF-30 have some advantages in lower cost, high water reducing rate （19.7%） and optimum early strengths. Moreover, TGA-DTA and SEM analysis were adopted to research the NF-30 modified concrete on hydyation mechanism. The analysis show that, compared with NF, there are a large number of hydration products such as Ca （OH）2, C-S-H, AFt etc of NF-30, the structure of NF-30 is dense and the performance is good.

Coal flotation using wash oil as a new type of collector

The use of wash oil as a coal collector is proposed to overcome the disadvantages of regular collectors in coal slime flotation. These disadvantages include high price, limited sources and high consumption. The effect of additives on flotation was studied and an innovative ＂one rough separation--one cleaning separation＂ flotation technology was developed. The experimental resuits show that the clean coal ash content decreases by about 1.36% and the clean coal yield declines by around 10% with the application of the depressant. There is an increase of 3.76% in the yield of clean coal and a decrease of 0.40% in the ash content caused by utilizing a dispersant. An ultimate product having an ash content of 10.78% and yield of 70.12% can be attained using a combination of dispersant and depressant. The use of this new technology decreases the ash content by 1.21%, decreases the yield by 2.80% and an increases the coal flotation perfect index by 2.03%. Compared to common flotation, the utilization of the new technology reduces ash by 0.17%, increases yield by 5.3% and increases perfect index by 4.18%.