Study On Sulfur Fixation Technology Of Briquette And Its Application

Coal,as China's main energy source,emits a large amount of SO₂ and other polluting gases during combustion.In recent years,the pollution problem of civil coal-fired SO₂ has been increasingly intensified.The briquette sulfur fixation technology is simple in process and low in cost,which is beneficial to the clean and efficient combustion of civil coal.The choice of sulfur-fixing agent is the most critical factor affecting the sulfur-fixing effect of briquette sulfur-fixing technology.However,there are few studies on civil briquette sulfur-fixing agents,and the commonly used sulfur-fixing agents have the problems of sintering inactivation in high temperature section,secondary release of SO₂ by decomposition of sulfur-fixing products.In this paper,the dry waste calcium carbide slag from a chemical plant in Xiyang,Shanxi was used as the main sulfur-fixing agent to prepare civil clean coal,and the combustion sulfur-fixing test was conducted.Taking sulfur-fixing rate as the evaluation index of sulfur-fixing effect,the effects of calcium-sulfur molar ratio,calcium carbide slag particle size and combustion temperature on the sulfur-fixing effect of calcium carbide slag were studied respectively.And the influence of Fe?NO₃?₃,V₂O₅,Na₂CO₃ and KMnO₄ four sulfur fixing aids on briquette sulfur fixing at 1050?.Determine the best reaction conditions and proportion of sulfur fixing agent and auxiliary agent for civil briquette of calcium carbide slag;The practical performance was tested and the ash and slag after combustion were characterized by XRD and SEM to explore the mechanism of sulfur fixation.After that,the practical application of civil briquette was tested.The main results are as follows:?1?Ca/S is 3.5,the particle size of calcium carbide slag is selected between 50 mesh and100 mesh,and the sulfur fixation rate can reach 65.7%at a burning temperature of 950?;The sulfur fixation effect of adding Fe?NO₃?₃ and V₂O₅ is not good.When adding Na₂CO₃ and KMnO₄,which account for 0.2%of briquette quality and 1%of briquette quality,the sulfur fixation rate is 55.7%and 57.3%respectively at the combustion temperature of 1050?.?2?Sampling and testing the practical performance of the above coal briquettes all exceeded the national standard for civil briquette.In addition to CaSO₄,the sulfur-fixing products also generate a new sulfur-containing phase CaAl₆?SO₄?₄?OH?₁₂,which is wrapped around CaSO₄and inhibits its decomposition.KMnO₄ as a combustion aid provides active oxygen and accelerates the reaction process of SO₂ and calcium carbide slag;Na₂CO₃ changed the lattice structure of calcium carbide slag,making its pore size distribution conducive to sulfur fixation.?3?In the actual industrial production of briquette,it is found that the concentration of SO₂ emission is significantly reduced after adding sulfur-fixing agents and additives;In order to save costs,coal slime and anthracite are mixed to prepare briquette.When the mass ratio of slime and anthracite is 3:7,the SO₂ removal rate reaches 60.14%,and their performance reaches the national standard for civil briquette.