Study On Preparation Of Two Kinds Of Composite-bentonite Particle And The Treatment Of Mn In The Mine Wastewater

Mine waste water contains heavy metal ions, including the removal of manganese is morecomplex. In recent years the clay minerals for the adsorption of heavy metal ions has become aresearch hotspot of mine wastewater treatment, and developing a highly efficient,environmentally friendly, cheap, easy to solid-liquid separation of mineral materials is the key ofsuch method. Bentonite, which have a special effect for adsorption of heavy metal ions, isroasted by high temperature and prepared into two kind of bentonite composite particles, andstudied that the particle preparation process、influence factors、effect and mechanism ofmanganese removal、adsorption influence factor、competitive adsorption、adsorption isothermmodel、adsorption kinetics、regeneration of sodium sulfide to develop a high clay adsorbentparticles of manganese removal and new method.The results show that:1)The best preparation conditions of bentonite-fly ash composite particle is: the mixproportion of bentonite and fly ash is5:5, and the additive dose is10%, preheating temperatureis400℃, preheating time is60min, roasting temperature is600℃, the roasting time is10min;Compared with original soil,the effect of manganese removal can reach25.28%，compositeparticle have high strength,samll loss rate,the impact factor is as follows: the additive dose＞themix proportion of bentonite and fly ash＞preheating temperature＞preheating time.2)The best preparation process of bentonite-adsorption granules: bentonite and fly ashmixture ratio is8:2, the additive dose is5%, roasting temperature is500℃, roasting time is60min.Compared with original soil, effect of manganese removal has little difference, bentoniteand fly ash have high strength, lower loss rate;3)It revealed manganese removal mechanism of the particle: high temperature roastingpromoted the particle surface to become loose and porous, surface area increased, the adsorptionpoint of manganese increased, so that the adsorption capacity of adsorbents and cation exchangecapacity significantly improved, while the particle release basicity and SiO2in the particles withthe admixture of sodium generate sodium silicate,which with manganese producesilicate-manganese complex formation lead to surface precipitation adsorption, is moreadvantageous to the removal of manganese.4)The adsorption of bentonite particles adsorption experiments show that: with the increaseof the adsorption time, adding amount, manganese removal rate increases gradually, and adsorption removal rate is fast in the initial of the response; in the condition fo weak acid andhigh concentration manganese, which is more conducive to the adsorpion of manganese iron andmanganese; competitive adsorption, iron is more preferentially adsorbed than manganese;adsorption isotherm model accord with Langmuir model; adshorption kinetics is compatible withquasi two level dynamic model; sodium sulfide can make the adsorbent regeneration.Compared with raw bentonite, two kinds of particles realizes separation of sludge fromwastewater、resource utilization of solid waste, and manganese removal effect is good, highstrength, small loss rate, low cost, is a promising manganese adsorbent particles.