An improved method for producing high-purity quartz (Qtz) and potassium feldspar (Kfs) concentrates was developed using various chemical reagents. Froth flotation experiments on a Qtz–Kfs mixture showed that quartz could be selectively floated from Kfs in diluted hydrofluoric acid (HF) using a frother. Similarly, feldspar could be selectively floated from quartz. Recovery rates depended on reagent choice, pH levels, HF modifier dosage, and HF conditioning time. High recoveries and good grades were achieved for both quartz and feldspar at low pH levels. Among the five collectors tested, Brij C20 showed the highest recovery when used in conjunction with HF and a frother alone and a concentrate containing 82.8% quartz was obtained at a 96% recovery rate. Good recoveries were also achieved with collectors like Duomeen C and Flotigam V4343 for floating K-feldspar, with a Kfs concentrate of 99.9% purity at a 94% recovery. Lilaflot OT 55 and Duomeen TDO were less effective. The concentration of HF was 22 kg/t, which implies an important reduction with respect to the earlier research.