In the tungsten mine of Wolfram Bergbau und Hütten AG, Mittersill large quantities of waste rocks and tailings are produced due to the geometry of the deposit and the low content of ore. Parts of the worthless material are used to backfill underground cavities created by the mining. Inter alia, a pumping backfill is introduced, which consists of the residues of the flotation plant and a purchased binder. In the course of this work, the flotation residues of the company were investigated with the aim of developing an alternative recipe for the pumping offset used in underground mining. Instead of a conventional cement-based binder, the flotation effluents should be activated with a solution of NaOH and Na2SiO3 and stimulated to solidify. The test specimens prepared from the flotation effluents and alkali silicate containing solution reach 28-day compressive strengths of 30 MPa when cured at a temperature of 60 °C. At room temperature cured samples achieve up to 15 MPa compressive strengths. Additions such as blast furnace slag or calcium hydroxide can increase both the early strength and the final strength. When ground flotation was used, compressive strengths> 50 MPa could be measured. Due to the large analytical effort, the reaction products of the curing process could not be investigated within the framework of this diploma thesis. The question of whether solidification by geopolymerization, alkaline activation or simple binding through water glass takes place, can therefore not be answered and requires further investigation. With regard to a cementless pump offset, the results of this work show that a corresponding product can be made. In addition, further applications can be discussed as an alternative binder.