Feldspar is separated from quartz by two flotation methods in Japan.
In a conventional method, feldspar is floated using an amine collector with hydrofluoric acid. The other method uses normal alkyltrimethylene diamine acetate (NATMD) and sodium petroleum sulfonate (PS) as collectors without using hydrofluoric acid. The purpose of this paper is to investigate the effect of particle size of feldspar and quartz on their flotation by both methods. Eight different size fractions of feldspar and quartz (-210+149, -149+105, -105+74, -74+53, -53+44, -44+37, -37+10, -10Em) were used for flotation tests. Flotation tests were carried out using artificial mixtures of both minerals (1: 1 by weight). Experimental results are summarized as follows.
1) In the case of mixtures containing -210+10μm fractions of feldspar and quartz, successful separations were obtained using dodecylamine acetate (DAA) with hydrofluoric acid. Fine quartz (-10μm) especially reduced the flotation recovery of coarse feldspar (+105μm). A large amount of DAA and sufficient activation of feldspar by hydrofluoric acid were required to separate feldspar from quartz when the flotation feeds contained fine quartz or fine feldspar, orboth.
2) The non-hydrofluoric acid system performed well when the flotation feeds contained -210+53μm fractions of feldspar and quartz. Fine quartz reduced the floatability of feldspar remarkably, and a large amount of collectors was required to float feldspar. Fine feldspar floated well when a mixed ratio of NATMD to PS is 2: 1, and fine feldspar was separated from coarse quartz (-210+105μm). The separation of fine feldspar from quartz (-105μm) was difficult because the floatability of quartz increased with the reduction of its particle size.
