Acid Mine Drainage Technology Research And Design

One acid mine drainage pollution source is located in the upstream water of theHanzhong city, where some parts of the abandoned mining pit perennial has pit chungwastewater flow. Its pH value is2⁴, and contains iron, copper, zinc and other metalions. A great quantity of acidic waste water flowing into the river of Pingcang,seriously interfere with people’s normal production and life in the downstream. Thecrude sewage treatment facilities of this mine, which can’t meet the requirements ofenvironmental protection, in view of this, it should build a new set of sewagetreatment facilities. The traditional method has some problems,such as large dosage,large amount of slag, slag moisture content high,slag dewatering difficulty, severescaling,peration maintenance workload big, etc. According to these problems, inorder to reduce the chemical dosage to and reduce the amount of slag, this study iscarried out in terms of chemical dosage methods chemical types and slag returnmethod.The main results of this study are:1. In the experiment of slag return, about30%mine wastewater treatment’sdosage were saved in the case of acid of slag return, and this can greatly reduce theamount of slag. The results are applied to the design of LB-HMR reactor’s parametersoptimization, to realize the selection of different density slag exclude and return, copewith the change of water quality and quantity.2. The part of lime which wasn’t completely decomposition burnt can be used asproduct of neutralization’s endogenous core such as Fe（OH）₃, gypsum （CaSO₄·0.5H₂O）,etc, It can provide nuclear carrier for precipitation agglomerate,makes the condensedslag particles more compact, then reduce the moisture content of slag. At the same time, slag particle size increases and the dehydration properties of slag improves.3.Through PAM dosing experiment, the best PAM type of the acidic minewastewater is positive, the best additive quantity is5PPM. At the same time, throughthe combination of slag return and PAM experiment, when the slag return ratio is0,PAM can reduce the moisture content of slag; when the slag return,dosing PAMwould improve the moisture content of slag. Based on the theory of this experiment,PAM dosing cylinder is seted in inside tube at the design of LB-HMR reactor, when thetiny slag quantity overflow from upper barrel is large, we can dose PAM to improvewater quality.4. Tank for pretreatment is for adjusting flow and water quality, and is the mainplace where water, remedy and slag contact reaction. From rely on gravity flow into thechannel flow in the raw water, by the dosing pump room upgrade to lime milk, by slurrypump from slag circumfluence pool backflow slag and the slag concentration pool andplate and frame filter press backflow to the wastewater was concentrated in the in theprereaction pool mixing, reaction. And in the pool, through the way of adjust the pipevalve to regulate water, medicine and slag’s mixture ratio, we can make treatment moreflexible.5. LB-HMR reaction pool is core equipment of the whole process, the equipmentmainly proceed potions neutralization, flocculation precipitation, slag adsorption andseparation of mud and other processing. In the device internal set up different inlet,precipitation area and mud collecting area, in addition adding the place for lime dosingand PAM dosing. We can choose different operation modes according to differentrequirements of water quality and quantity.