I. Decrease of Integrated Cost
(1) Waste materials that do not contain harmful heavy metals and produce harmful acids and salts reduce the amount of wastewater discharged and the cost of wastewater treatment. The content of phosphate in phosphating solution is about 15 000 *10-6, and the content of zinc, nickel and manganese is about 3 000 *10-6. When the backwash reaches the dynamic equilibrium of overflow, the wastewater contains about 1500 *10-6 phosphate, 300 *10-6 zinc, nickel and manganese, and the cost of wastewater treatment is about 8 yuan/t. Silane contains no phosphorus, zinc, nickel and manganese. Silicon content is about 40 *10-6 and zirconium content is about 200 *10-6. When the backwash reaches the dynamic balance of overflow, the wastewater contains 4 *10-6 silicon and 20 *10-6 zirconium, and the cost of wastewater treatment is less than 1 yuan per ton. Taking a domestic conventional air conditioning treatment line with an annual production capacity of 3.5 million feet as an example, about 2 L wastewater is produced per square metre and 7,000 tons of wastewater are treated annually. The cost of Phosphating Wastewater treatment is 49,000 yuan more than that of silane.


(2) Silane treatment can be carried out at room temperature without heating; basically no slag, no slag cleaning and corresponding chemicals, no heat exchanger and corresponding chemicals, no slag cleaning chemicals emissions. This greatly reduces the workload. The phosphating heat energy consumption is about 50 yuan/k_when the working temperature of phosphating is 35 ~C, while that of silane (heating up to 15 ~C only in winter) is about 10 yuan/k_. Phosphating costs 140,000 yuan more per year than silane in terms of 3.5 million cycles per year.


(3) Energy saving. Silane does not need the step of adjusting the meter. It can save 28,000 yuan per year by adjusting the spray pump 4 kW/h (working 2 hours per day), 350 days per year and electricity price 1 yuan/kW_h.


II. Decrease in maintenance costs
1. Phosphating liquid needs to be transported to reserve sedimentation for slag removal every 2-3 months; every 3-6 months, after tank inversion, phosphorus slag in the pipeline with good tank wall should be removed by chemical method; nozzles need to be removed and cleaned with chemicals once a week; heat exchangers need to be cleaned chemically every 2-4 weeks, otherwise the effect of phosphating treatment will be affected. The above maintenance work was cancelled after silane treatment.


2. The tank liquid control is simpler and reduces the workload of on-site feeding and testing.


3. Phosphating needs three steps: degreasing, surface adjustment and phosphating. The surface adjustment needs to change trough every week, and PH and conductivity should be tested. The phosphating trough needs to detect free acid, total acid, promoter content, fluosilicic acid content and zinc, nickel and manganese ion content. Silane treatment consists of two steps: degreasing and silane treatment. Silane tank only needs to detect pH, conductivity and activation point. The test results of salt spray resistance and film adhesion after powder spraying reach 500 hours.