The Pretreatment Experiment Study Of Reverse Osmosis Concentration Of Rare-Earth Ammonium Chloride Waste Water

In the paper, the chlorine ammonium wastewater treatment and reclamation are researched for Baotou rare-earth smelting plant. Rare-earth chlorine ammonium wastewater including plain liquor and lotion is bringed in the producing unitary carbonic acid rare-earth, in which high thickness plain liquor is evaporated and crystaled directly and low thickness lotion is discharged in a majority of enterprise. At present there aren't fit treatment method for the lotion because amount of water is big and energy consumption is high, enterprise is difficult to bear if the lotion is evaporated and crystaled directly. Therefore the lotion is evaporated and crystaled after being concentrated by reverse osmosis technics.With the development of the RO technology and the decrease of RO's cost, the reverse osmosis is widely applied in the field of Rare-earth industry's wastewater treatment. Because the RO is strict in water quality of influent water. How to prevent the RO pollution and stopping the RO element by calcium ion as well as magnesium ion in the concentrated wastewater is the difficult point. Therefore, the pretreatment test is major contents in the subject.Firstly, the thesis introduces the pretreatment experiment. According to the quality of chlorine ammonium wastewater and the request for influent water, the pretreatment experiment includes following multi part experiment that coagulating sedimentation, filter, adsorption, intenerating scale, inhibitor. (1) The experiment of coagulating sedimentation that AC, PAC, PAM is singly input and PAC and PAM are compound confected. Through the experiment of coagulating sedimentation, the wastewater's turbidity reduces to below 0.5 NTU. The method can remove partial pollution, so it acts as the auxiliary treatment way. (2) The adsorption experiment that the dynamic experiment and the static experiment are made with adopting ashes dreg and active carbon jointly adsorption. The experiment's results show the wastewater's oil decrease to below 0.5 mg/L and the wastewater's COD decrease to below 0.5mg/L and the wastewater's turbidity decrease to below 0.5 NTU through jointly adsorption. The method can satisfy the request for influent water. (3) The hardness of water can reduce to percent of 40 through inputting medicament(ammonia).the saturation index of concentrated solution is 1.28,the wastewater concentrates 4 times and does not fouling through inputting 3.3mg/L membrane as well as an amount of acid. It is feasible to adopting RO system to treat chlorine ammonium wastewater.Secondly, the condensation system's design of RO is introduced. The determination of the design parameter, the RO, the RO element and the choice of RO performance parameter and the determination of the RO element's quantity and the determination of the RO element's permutation and combination are elaborated.On the one hand, the subject reclaims valuable ammonium chloride, on the other hand, water is recycled and improve the utilization ratio of water. Therefore, the method of the RO pretreatment not only saves water resources, but also eases environmental pollution and ecological damage. At the same time, it has remarkable economic benefit social benefit.