【作者】 张侠；

【导师】 何玉凤；

【作者基本信息】 西北师范大学 ， 分析化学， 2011， 硕士

【摘要】 随着社会的加速进步、科技的迅速发展与环境问题的日益突显,从矿产资源高效回收贵金属,以及工业生产、人们生活过程中所产生废弃物的回收利用显得十分重要。马铃薯淀粉生产过程中所产生的大量副产物——马铃薯渣富含多种功能物质,具有较高的开发和利用价值,但是,目前只是被低级利用,如作为饲料或肥料,有些企业的鲜马铃薯渣因不易储存和运输,难于脱水干燥,腐败后产生恶臭,造成较严重的环境污染。为了解决马铃薯渣开发利用的难题,本论文采用螯合法从马铃薯渣中提取可溶性膳食纤维(SDF),并分析探讨其的组成与特性,以期拓展其应用领域,提高附加值。另外,本论文采取了离心重选、直接氰化技术对某铜矿中伴生金、银进行了回收利用研究,以期提高贵金属的回收利用率,减少资源浪费。论文首先在对膳食纤维结构、性质及提取方法的研究进展进行综述的基础上,介绍了从马铃薯渣里提取膳食纤维的进展。其次,以六偏磷酸钠为螯合剂,采用螯合法研究了从马铃薯淀粉渣中提取膳食纤维的方法,通过单因素实验、正交实验和极差分析,考查了提取温度与时间、溶剂与螯合剂用量的影响,确定了提取可溶性膳食纤维的最佳配料比和反应条件,可溶性膳食纤维最取率可达58%。第三,采用红外光谱、扫描电镜、元素分析以及生化反应等方法对提取的SDF组成、结构及形貌进行了分析,并研究了SDF水溶性、持水力、膨胀力、离子交换能力等性质。发现螯合法提取的SDF主要是由半乳糖、葡萄糖、甘露糖等短链糖类组成;通过扫描电镜对SDF微观结构的观察和对比,发现SDF的表面呈剥离的、片状粗糙的纤维结构,这样就便于溶液渗透到SDF网络结构中,有利于阳离子交换和亚硝酸根离子的吸附;在pH=7,37℃条件下SDF具有良好的水溶性(56.15%)、较高的持水力(7.72 g/g)和膨胀力(8.56 mL/g)。第四,采用不同的离心重选机对碎磨至200目的铜矿粉进行离心重选,并通过单因素实验考查了反冲水量、转速、富集时间对提取率的影响,确定了最佳条件。金精矿中金品位最高达2000 g/t,金的重选回收率可达55.6%,在精矿中的富集比可达618倍。若离心重选与浮选法联合使用,可以使铜矿中伴生金的总回收率达到60-70%,为企业带来显著的经济效益。第五,采用直接氰化浸出法从铜精矿中提取含量较高的伴生银。采用滴加的方式加入NaCN,并通过控制滴速来控制NaCN的瞬间浓度,从而提高NaCN的利用率。发现当反应时间为48 h,NaCN用量大于20 kg/t时,银的浸出率大于70%。研究结果为进一步工业化生产提供依据。更多还原

【Abstract】 With the rapid development of society and technology, the environment problem is mounting. As a result, it is important for us to recycle the precious metals from the mineral wealth and the rubbish arised by the industrial production and human life. Potato pulp is a kind of byproduct in the process of potato starch production, Potato pulp is not only much nourishment in various functional substance, but also contains higher value of exploitation and use. However,Potato pulp has been seldom made use of to advantage. For example it is usually used for Fodder and Fertilizer. And, the seirous environmental pollution is caused by rotten potato pulp due to hard store and transport and to dehydration. In order to solve the problem of exploitation and utilization of potato pulp, sodium hexametaphosphate (SHMP) as a chelating agent used to extract soluble dietary fiber (SDF) from potato pulp in this study. Moreover, the composition and properties of SDF are discussed comprehensively and systematically to broaden the application field and enhance its auxiliary value. In addition , the technology of centrifugal reelect and directly cyanogenation was applied to recycle and utilize the associated gold and silver in the copper deposit to raise the utilization rate of precious metal and reduce the resources waste.In the present essays, firstly, based on the summary of the structure and properties of the SDF, we make an introduce advance for extracting the SDF from the SHMP. Secondly, the method extracting the SDF from the SHMP was studied by the chelation used the sodium hexametaphosphate (SHMP) as a chelating agent. Moreover, through orthogonal experiments and single factor and experiments analysis of variance, we fixed the optimal conditions for extracting the SDF. The extraction percent of SDF was achieved58%.Thirdly, the surface topography and composition of SDF were analyzed by IR, SEM, Analysis of Elements and biochemical reaction. Meanwhile, the water-solubility, expansibility, retention ability and ion-exchange ability of SDF were investigated.The soluble dietary fiber in Potato pulp exhibited good solubility in water (56.15%), the high expansibility (8.56 mL/g) and water-holding capacity (7.72 g/g) reached the highest under pH = 7 and 37 ?C. Fourth, We reelected raw ore whichthrough 200 mesh occupied 60% by using 12 inches Nielsen MD3 centrifugal heavy separator and 12 inches domestic centrifugal heavy separator. It was found that the production efficiency and stability of domestic centrifugal heavy separator was favorable, therefore, it can be used in industrial production. The optimum conditions were determined by means of single factor experiment. The details as below, 800 rpm of centrifugal force, 20 L/min of recoil hydraulic and 120 min of accumulation time uninterruptedly run 60 h. The amount of obtained gold concentrate is 150 kg. The average gold grade is 671 g/t. The recovery is 52.21% and enrichment ratio is 583 in concentrate.Fifth, the high content of associated silver was extracting from the Copper Concentrate by cyanogenation Leaching Procedure. In order to raise the utilization rate of NaCN, we control the instantaneous speed of NaCN dropill by dropping. The results showed that the leaching rate of silver was more than 70% with the 48 hours of reaction time and the consumption of NaCN greater than 20 kg/t. Key words: Potato Pulp, soluble dietary fiber, centrifugal re-election, Copper concentration, Gold extraction, Silver extraction.更多还原