CAJ | 학술논문

在废旧电路板热解处理过程中,溴化阻燃剂分解产生大量溴化氢,为了减少溴化氢对热解设备和环境的危害,提出了碳酸钙吸附分离溴化氢的处理工艺,生成的溴化钙通过水的浸取、过滤、蒸发、浓缩等过程,获得了质量分数为52%,密度为1.7 g/mL的溴化钙水溶液.研究了热解温度、碳酸钙用量对溴化钙产率的影响规律及溴化钙的浸取工艺条件.热解吸附试验表明,碳酸钙与电路板的质量比为1.2～1.4,热解温度约为600 ℃时,溴化钙的产率最高可达86%;浸取试验表明,溴化钙的单次浸取率随浸取剂的浓度增大而降低,随温度升高而提高.溴的回收率主要取决于溴化钙的产率,通过选择合适的热解吸附条件,废旧电路板中溴的总回收率高于80%,所回收的溴化钙液体产品主要技术指标接近同类市售产品.
재폐구전로판열해처리과정중,추화조연제분해산생대량추화경,위료감소추화경대열해설비화배경적위해,제출료탄산개흡부분리추화경적처리공예,생성적추화개통과수적침취、과려、증발、농축등과정,획득료질량분수위52%,밀도위1.7 g/mL적추화개수용액.연구료열해온도、탄산개용량대추화개산솔적영향규률급추화개적침취공예조건.열해흡부시험표명,탄산개여전로판적질량비위1.2～1.4,열해온도약위600 ℃시,추화개적산솔최고가체86%;침취시험표명,추화개적단차침취솔수침취제적농도증대이강저,수온도승고이제고.추적회수솔주요취결우추화개적산솔,통과선택합괄적열해흡부조건,폐구전로판중추적총회수솔고우80%,소회수적추화개액체산품주요기술지표접근동류시수산품.
The paper has carried the investigations and experiments on the effects of pyrolysis temperature and weight ratio of calcium carbonate to WPCBs on the yield of calcium bromide along with our study of the processing conditions of extracting calcium bromide. As is known, most of the bromine to be recovered here present in brominated flame retardant exist in the form of hydrogen bromide during the pyrolysis of waste printed circuit boards(WPCBs), with the hydrogen bromide formed to cause severe equipment corrosion and environmental pollution. Therefore, in order to reduce the damage caused by the hydrogen bromide, we have developed actually a new process of adsorbing and separating hydrogen bromide from calcium carbonate. Calcium bromide resulted in the given process can be extracted with water, and then 52% wt calcium bromide solution with density of 1.7 g/mL could be obtained through filtrating, evaporating and concentrating of the calcium bromide extraction solution. The experimental results of pyrolysis and adsorption indicate that the maximum yield of CaBr_2 was 86%, when the calcium carbonate weight ratio to WPCBs remains between 1.2 to 1.4 with the pyrolysis temperature at about 600 ℃. In addition, the extracting experimental results also show that the single extraction rate of calcium bromide which tends to get reduced with the increase of the extraction agent content whereas increased with elevation of extraction temperature. Moreover, the calcium carbonate after being regenerated can be recycled to adsorb HBr. However, there remains a small amount of calcium bromide residue in the calcium carbonate that may not be likely to cause any loss of bromine duo to the recycling of calcium carbonate. Thus, the recovering rate of bromine mainly depends on the yield of calcium bromide, with the total recovering rate of bromine expected to get over 80% by the optimal pyrolysis and adsorbing conditions. The main specifications of calcium bromide solution prepared from our experiments with WPCBs are approximate to the level of commercial calcium bromide solution product.