Mixture comprising a sulfidizing agent and an alkalinizing agent and its use

Abstract

The present invention relates to a process and mixture for the safe dosing of a sulfidizing agent in a mineral flotation process that comprises the prior preparation of a mixture of sulfidizing agent with at least one alkalizing agent. In this way, the production of hydrogen sulfide is prevented, allowing the mixture to be safely used in mining operations located in enclosed places such as caves or in operations close to populated areas.

1 . Process for the dosing of a sulfidizing agent or ionizing sulfide in a mineral flotation process in a safe and manageable manner, CHARACTERIZED in that it comprises the prior preparation of a mixture of sulfidizing agent with at least one alkalizing agent. 
     
     
         2 . The process according to  claim 1 , CHARACTERIZED in that the ionizing sulfide or the sulfidizing agent is selected from the group consisting of sodium hydrosulfide, sodium sulfide, potassium hydrosulfide, potassium sulfide, ammonium hydrosulfide or ammonium sulfide, potassium, sodium, calcium, magnesium or ammonium polysulfides or a mixture thereof. 
     
     
         3 . The process according to  claim 1 , CHARACTERIZED in that the alkalizing agent is slaked lime slurry. 
     
     
         4 . The process according to  claim 3 , CHARACTERIZED in that the sulfidizing agent is added directly in the slaked lime slurry preparation plant. 
     
     
         5 . The process according to  claim 1 , CHARACTERIZED in that the slaked lime slurry is prepared first and then mixed with the sulfidizing agent. 
     
     
         6 . The process according to  claim 4 , CHARACTERIZED in that the mixture of slaked lime slurry and the sulfidizing agent is carried out in the slaked lime dosing tank or just before dosing the lime to the flotation stage or to the grinding stage. 
     
     
         7 . The process according to  claim 4 , CHARACTERIZED in that the mixture of slaked lime slurry and the sulfidizing agent is carried out outside the flotation zone in a ventilated environment. 
     
     
         8 . The process according to  claim 1 , CHARACTERIZED in that the slaked lime is prepared in a proportion between 5% and 30% lime with 95% to 70% water. 
     
     
         9 . The process according to  claim 4 , CHARACTERIZED in that the mixture of the sulfidizing agent with slaked lime slurry can be dosed at different stages of the flotation process. 
     
     
         10 . The process according to  claim 8 , CHARACTERIZED in that the mixture of the sulfidizing agent with the slaked lime slurry is dosed at the grinding stage. 
     
     
         11 . The process according to  claim 8 , CHARACTERIZED in that the mixture of the sulfidizing agent with the slaked lime slurry is dosed at the flotation stage. 
     
     
         12 . The process according to  claim 8 , CHARACTERIZED in that the mixture of the sulfidizing agent with the slaked lime slurry is dosed between the grinding stage and the flotation stage, in one or more additions. 
     
     
         13 . The process according to  claim 1 , CHARACTERIZED in that the dose of the sulfidizing agent must be less than a dose that generates depression of the sulfide to be recovered. 
     
     
         14 . The process according to  any of the preceding claims , CHARACTERIZED in that the sulfidizing agent is sodium hydrosulfide. 
     
     
         15 . The process according to  claim 13 , CHARACTERIZED in that sodium hydrosulfide is added to the slaked lime slurry in a dose between 20 and 300 grams on a dry basis per ton of mineral fed to the process, preferably between 60 and 100 grams on a dry basis per ton of mineral. 
     
     
         16 . The process according to  claim 1 , CHARACTERIZED in that the metal to be recovered is copper. 
     
     
         17 . The process according to  claim 1 , CHARACTERIZED in that the sulfidizing agent is mixed with an alkaline compound other than lime, such as sodium hydroxide. 
     
     
         18 . The process according to  claim 1 , CHARACTERIZED in that the sulfidizing agent is mixed with an alkaline compound other than lime, such as sodium bicarbonate. 
     
     
         19 . Mixture for a mineral flotation process, CHARACTERIZED in that it comprises a sulfidizing agent and an alkalizing agent. 
     
     
         20 . The mixture for a mineral flotation process according to  claim 19 , CHARACTERIZED in that the alkalizing agent is selected from slaked lime slurry, sodium hydroxide, sodium bicarbonate or a mixture thereof. 
     
     
         21 . The mixture for a mineral flotation process according to  claim 20 , CHARACTERIZED in that the alkalizing agent is slaked lime slurry. 
     
     
         22 . The mixture for a mineral flotation process according to  claim 21 , CHARACTERIZED in that the mixture of slaked lime slurry with the sulfidizing agent is carried out in a proportion of (lime on a dry basis):(sulfidizing agent on a dry basis) between 22:1 and 4:1. 
     
     
         23 . The mixture for a mineral flotation process according to  claim 21 , CHARACTERIZED in that the slaked lime slurry is prepared in a concentration of lime in water between 4% and 20% by weight. 
     
     
         24 . The mixture for a mineral flotation process according to  claim 21 , CHARACTERIZED in that it has a pH of at least 12. 
     
     
         25 . Use of the mixture according to  claim 19 , CHARACTERIZED in that it serves for the flotation of minerals safely avoiding the emission of hydrogen sulfide, keeping the sulfidizing agent in solution and without crystallizing. 
     
     
         26 . The use according to  claim 25 , CHARACTERIZED in that it serves for the use of a sulfidizing agent in plants located in underground caves and/or near populated areas.