The Purification And Fine Processing Of Bentonite Of Faku

In this paper, fine processing products of bentonite were developed, by using the natural bentonite mineral of Faku in Liaoning Province. After the structure feature and basic characteristic of bentonite were described and combined with the requirement of bentonite in the preparation of the polymer/layered silicate nano-composites, the mechanism, methods and effect of sodium modification, purification and organic modification were discussed.In this paper, the characteristic of raw ore was analysed. The results provided the basis for the next stage processing treatment. It was found that the raw ore was Ca-bentonite and every physico-chemical performance index was very low, so, it was necessary for sodium modification. It was also found that the content of SiO2 and montmorillonite was 75.32% and 73.5%, respectively, therefore, it needed to purify. The researche showed that, it was difficult to removal the cristobalite for its fine grain size, thereby, it suggested that sodium modification should be taken before purification.The effect of various Na-modifide agents and the economic factor had been studied. The result showed that Na2CO3 was the best choice. In this paper, wet process was used. And the experiment showed that the optimum operating conditions:the addition amount of Na2CO3 was 5% of raw ore quality, the reaction time was 1.5h, the reaction temperature was 70℃, the pH value was 8, and the slurry density was 10%.Organic modification required the content of montmorillonite of the material was more than 90%. So, it was very important to purity the bentonite. In this paper, wet process was used. And the experiment showed that the optimum operating conditions:the concentration of dispersant was 0.25%, the pH value was 8, and the sedimentation time was 2.0h.The physico-chemical performance such as colloid index, expand volume, the cation exchang capacity (CEC) and so on of Na-bentonite and purification bentonite was tested. The interlayer spacing (d001) of Na-bentonite reduced to 12.40A from 15.48A of raw ore. In addition, the content of montmorillonite of purification bentonite was up to 98.8%, and every index was better than the standard of first grade product, which indicated that the product had met the requirement of organic modification.In this paper, using the purification bentonite as the material, expensive modifier with cheap caprolactam were used to synthesize new-type organobentonite with good performance, in the principal of efficient, cheap and simple. In the end, it showed that octadecyltrimethyl ammonium combinding with caprolactam was the best compound modifying agent, and the optimum proportion was five to one. The product had the largest interlayer spacing and organic rate. Therefor, it was more suitable than others for preparation of the polymer/layered silicate nanocomposite.In the experiment, the XRD,SEM,IR,DTA and so on characterization means were used to analyse the mechanism of sodium modification, purification and organic modification. It provided basis for developing the fine processing products of Faku bentonite. And it is helpful to widen its practical range, and become the resource advantage to ecomomic advantage.