Study On The Mechanism Of Pressure Acid Leaching Treatment Of High Silicon Manganese Fume To Extract Manganese And Silicon

As a by-product of manganese alloy smelting,manganese fume has always been an important target for comprehensive utilization in the industry.Regardless of the environmental benefits or social benefits,the efficient recovery and utilization of manganese smelting dust is of great significance.This article takes the chemical reaction behavior of manganese and silicon under the acidic system of high silicon manganese dust as the research object.Based on the analysis of the mineralogical characteristics of the high silicon manganese dust such as phase composition,element distribution,and occurrence of manganese and silicon,etc.,Mainly study the reaction law of manganese and silicon phases in the acid leaching process of high silicon manganese fume;explain the thermodynamically stable forms of manganese and silicon under different temperatures and pressures,and reveal the thermodynamic conditions required for the process of manganese extraction and silicon precipitation;research pressurization The characteristics of the dissolution and sedimentation reaction behavior of the silicon phase in the acid leaching process of high-silico-manganese fume under high temperature,establish the regression equation of the reaction rate of silicon precipitation and various factors,and reveal the dynamic behavior mechanism of the pressure acid-leaching high-silico-manganese fume.The development of the thesis provides a theoretical basis for the transplantability of the pressure-enhanced extraction of high-silicon refractory resources and the application of the technology route of sinking silicon.The specific research content is as follows:(1)Use XRD,SEM,XRF and other analytical testing methods to conduct mineralogical analysis on the test samples of high silicon manganese soot and reducing agent pyrite.High silicon manganese dust contains the most Mn and K elements,reaching 33.62%and 26.07%,respectively.The content of Si is 12.06%.The main forms of manganese are MnO_1.88and MnO,with a content of 15.94%.The compounds are K₂O and SiO₂,the contents of which are 20.82%and 19.45%,respectively.The main compounds in the reducing agent pyrite are Fe S₂and Fe₂O₃,the contents of which are 49.86%and 39.97%,respectively.Other compounds with higher contents are CaO,MgO and SiO₂,with contents of 3.52%,2.96%and 2.43%,respectively.(2)The thermodynamic analysis and calculation of the process of high silicon manganese fume extracting manganese and silicon precipitation showed that during the leaching process,the reaction system needs to maintain a relatively high initial acid concentration in the presence of a reducing agent to achieve the leaching of Mn2+;the system contains hydrogen.When the high silicon manganese fumes are leached with sulfuric acid under pressure,the Mn²⁺in the solution will not be reduced to metallic manganese by hydrogen;when there is oxygen in the system,manganese tends to exist stably as Mn²⁺and Mn(OH)₂,and the low price of silicon State substances will become unstable and extremely easy to be oxidized.Under high temperature leaching conditions,in order to achieve the purpose of reducing the production of orthosilicic acid,the leaching system needs to maintain a relatively low initial acid concentration;as the temperature and pressure increase,Silica sol is gradually transformed into silica precipitation,which is easy to separate.(3)The atmospheric acid leaching and pressure acid leaching experiments of high silicon manganese fume were carried out respectively.The effects of reaction temperature,ratio of two ore,liquid-solid ratio,initial acid concentration,reaction time and pressure on the results of acid leaching of high-silico-manganese fumes were investigated.According to the experimental results,the optimized test conditions for pressure acid leaching of high-silica-manganese fumes are obtained:the ratio of two mines is 1:0.4,the ratio of liquid to solid is 5:1,the reaction speed is 500r/min,the initial acid concentration is 120g/l,and the leaching temperature is 160?.,The leaching time is 2h,and the leaching pressure is 0.8Mpa.After using this condition for high silicon manganese fume pressure acid leaching,the best manganese leaching rate can reach 96.1%,while the impurity elements silicon and iron leaching rates are2.11%and 5.86%respectively;for the atmospheric acid leaching test Six variables:initial acid concentration,reaction time,liquid-to-solid ratio,two-ore ratio,reaction temperature,speed,and finally obtained high-silica manganese soot manganese leaching rate optimization test conditions:initial acid concentration 160g/l,reaction time is the reaction The time is 120min,the ratio of liquid to solid is 5:1,the ratio of two minerals is 1:0.6,the reaction temperature is 90?,and the rotation speed is450r/min.At this time,the manganese leaching rate is 88.6%,and the impurity element silicon and iron leaching rates are respectively They are 7.09%and 7.69%.Comparing the leaching rate of manganese,silicon and other elements in normal pressure acid leaching and pressure acid leaching experiments,it can be seen that the application of pressure acid leaching technology has obvious advantages.(4)The kinetic analysis of the pressure acid leaching process of high-silico-manganese fumes was carried out using the mineral leaching kinetics principle.Mainly investigate the influence of temperature,stirring speed and pressure on the leaching of silicon-containing phases of high-silico-manganese fumes.The results show that:under fixed conditions:liquid-solid ratio 15:1,rotation speed500r/min,pressure 0.4Mpa,temperature 140?,The leaching activation energy of the silicon-containing phase of the high-silico-manganese fume dust is 1.1035KJ/mol^-1(less than 40KJ/mol^-1),which belongs to the diffusion control type.