Separation of azodicarbonamide from surface of diatomite by froth flotation

Abstract

The separation of azodicarbonamide (AC) from the surface of diatomite by froth flotation is investigated in this research. Pure samples of diatomite, AC and 1:1 mixtures of the two were floated in a lab-scale flotation cell with collector dosage, frother type and dosage, and pH varied to determine the optimum experimental conditions. The diatomite sample and products from flotation tests were characterized using scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDX). The results of the flotation tests indicate that there is less AC on the surface of diatomite after flotation compared to the feed, while the AC present in diatomite pores remains unchanged. Additionally, Fourier transform infrared spectroscopy (FT-IR) was employed to study the mechanism of interaction between reagents and minerals.

摘要

硅藻土是一种具有独特微孔结构的硅质沉积岩, 可用作吸附或填充材料。 偶氮二甲酰胺是工业上广泛应用的一种发泡剂, 将偶氮二甲酰胺填充到硅藻土孔隙中能改善硅藻土性能, 使其同时具有硅藻土和偶氮二甲酰胺特性, 覆盖在硅 藻土表面的偶氮二甲酰胺会影响改性材料的性能。 本文通过微泡浮选对硅藻土表面分离偶氮二甲酰胺进行了研究, 考察了捕收剂用量、 起泡剂种类和用量、 pH 值对分离效果的影响, 结果表明: 当起泡剂 MC-1 用量为 60 mg/L, 捕收剂煤油用量为 80 mg/L, pH 为 5 时, 效果最好, 偶氮二甲酰胺与硅藻土的上浮率之差达到 89.4%, 偶氮二甲酰胺的回收率达到 72.5%。 通过扫描电镜和能谱对浮选产品进行表征, 结果表明:与原矿相比, 浮选后硅藻土表面偶氮二甲酰胺大幅度减少, 硅藻土孔隙中偶氮二甲酰胺基本不变。 通过红外光谱研究了药剂与矿物之间的作用机理, 表明硅藻土与煤油之间不存在化学吸附, 浮选体系中煤油与 MC-1 形成一种乳状液, 吸附于硅藻土表面形成保护层, 防止药剂和矿浆与硅藻土孔隙内的 AC 相互作用。