彩涂板产品脱脂槽液如何控制
河北彩涂板产品脱脂槽液浓度控制方法是控制槽液的游离碱度。罐液的老化程度根据总碱度与游离碱度之比确定。当总碱度与游离碱度之比超过一定限度时,应丢弃罐液。该值的测定与预涂线圈的材料、金属表面固体杂质的类型以及处理温度有关。具体确定应根据实际情况,与用户共同确定。
1
河北彩涂板产品脱脂后的清洁要求是什么?
除油后,彩涂板必须用一个或多个阶段的热水喷雾进行冲洗。为了保持有效的冲洗效果,最好采用连续溢流法。
2
河北彩涂板产品脱脂设备的材料一般要求是什么?
除油储罐、夹套、泵、阀门、管道可采用低碳钢。丁腈橡胶、聚乙烯橡胶是循环泵或阀门等与脱脂剂接触的弹性材料的最佳密封材料。加热管最好采用80碳钢管或类似材料。换热器最好用抛光不锈钢,喷嘴也用不锈钢。应注意尼龙材料制成的刷辊耐60℃以上温度的困难。
三。
河北彩涂板产品如何去除钝化镀锌板上的钝化膜?
镀锌板可分为钝化板和涂油板。涂油板的脱脂浓度一般控制在1.5~5%,最佳为2~3%。当钝化板浓度控制在1.5%时,可以去除钝化膜。
4脱脂剂搅拌罐前应注意什么?
在准备油箱之前,必须检查油箱的清洁度。如有油污、灰尘、焊渣等异物,应提前清除,或用条形脱脂剂配制的0.4-0.6%浓度溶液清洗。
5铬对环境保护和人体有哪些危害?
Cr6+和Cr3+是传统转化液和带钢钝化剂的主要原料。Cr6+广泛应用于彩涂板和连续热镀锌板,具有良好的耐蚀性和附着力。但Cr6+对环境和人体的危害极为严重,表现在以下几个方面:1)严重污染周围环境,Cr6+的毒性比Cr3+高100倍左右,是一种强突变物质;2.铬对人体健康有害。铬对人体的危害是以Cr6+的形式渗入细胞,然后在细胞内还原成Cr3+形成致癌物,引起细胞突变和癌变。
6锆的测定方法是什么?
锆含量用“点”表示,即每100ml溶液消耗0.1mol/l EDTA标准溶液的毫升数。
锆的测定方法为:取浴液100ml,置锥形瓶中,加去离子水40ml,加热,加25%氨水13滴至出现明显不消失的沉淀,加水10ml,98%硫酸1.5ml,硝酸铝(九水)1g。煮沸3分钟后,用70℃的水稀释至200ml。冷却至50℃左右,加入4滴二甲酚橙,用0.1mol/l EDTA标准溶液滴定,在终点附近加入0.5g硝酸铝(九水),滴定至溶液呈黄色。
The concentration control method of degreasing tank liquid is to control the free alkalinity of the tank liquid. The aging degree of the tank liquid is determined according to the ratio of total alkalinity to free alkalinity. When the ratio of total alkalinity
to free alkalinity exceeds a certain limit, the tank liquid should be discarded. The determination of this value is related to the material of the pre coated coil, the type of solid impurities on the metal surface, and the treatment temperature. The
specific determination should be based on the actual situation and jointly determined with the user.
1. What are the cleaning requirements after degreasing?
After degreasing, the color coated board must be rinsed by one or more stages of hot water spray. The continuous overflow method is best used to maintain the effective rinsing effect.
2. What are the eneral requirements for the material of degreasing equipment?
Degreasing storage tank, jacket, pump, valve and pipeline can be made of low carbon steel. Nitrile rubber and polyethylene rubber are best used for sealing parts of circulating
pump or valve and related elastic materials contacting degreasing agent. 80 carbon steel pipe or similar material is best used for heating pipe. Polished stainless steel is best used for heat exchanger, and stainless steel is also used for nozzle. Attention
should be paid to the difficulty of brush roller made of nylon material To withstand temperatures above 60 ℃.
3. How to remove passivation film on passivated galvanized sheet?
Galvanized sheet can be divided into passivation plate and oiled
plate. The degreasing concentration of oil coated plate is generally controlled at 1.5-5%, and the best is 2-3%. The passivation film can be removed when the concentration of passivation plate is controlled at 1.5%.
4. What should be paid attention
to before degreasing agent mixing tank?
The cleanliness of the tank must be checked before the tank is prepared. If there are oil, dust, welding slag and other foreign matters, they should be removed in advance, or the solution of 0.4-0.6% concentration
prepared by strip degreasing agent can be used for cleaning.
5. What are the hazards of chromium to environmental protection and human body?
Cr6 + and Cr3 + are the main raw materials of traditional conversion liquid and passivator for strip.
Cr6 + is widely used in color coated sheet and continuous hot-dip galvanized sheet with good corrosion resistance and adhesion. However, Cr6 + has extremely serious harm to the environment and human body, which is reflected in the following aspects: 1)
seriously pollute the surrounding environment, the toxicity of Cr6 + is about 100 times higher than that of Cr3 +, which is a strong mutation substance; 2 Chromium is harmful to human health. The harm of chromium to human body is that it infiltrates into
cells in the form of Cr6 +, and then reduces to Cr3 + in cells to form carcinogen, which causes cell mutation and canceration.
6. What is he determination method of zirconium?
Zirconium content is expressed as "point", which is the milliliter
of 0.1mol/l EDTA standard solution consumed per 100ml solution.
The determination method of Zr is as follows: take 100ml of bath solution, put it into a conical flask, add 40ml deionized water and heat it, then add 13 drops of 25% ammonia water
until obvious and non vanishing precipitation appears, add 10ml of water, 1.5ml of 98% H2SO4 and 1g of aluminum nitrate (jiushui). After boiling for 3 minutes, dilute it to 200ml with 70 ℃ water. Cool to about 50 ℃, add 4 drops of xylenol orange, titrate
with 0.1mol/l EDTA standard solution, add 0.5g aluminum nitrate (jiushui) near the end point, and titrate until the solution is yellow.