表面活性剂对浸矿溶液表面张力的影响

采用加入表面活性剂的方法,改变溶液的表面张力,进而改善低品位磷矿的浸出效果;以吐温类表面活性剂的种类、用量作为影响因子,并用测量溶液表面张力的方法来评价其效果。结果表明:表面活性剂的用量、种类为较重要影响因子;不同种类、用量的表面活性剂可不同程度地改变浸矿溶液的表面张力,促进嗜酸氧化硫硫杆菌(At.t菌)对硫粉的氧化、产酸作用,改善浸磷效果。     

硫杆菌的驯化育种及对低品位磷矿的浸出

利用从广西某温泉采集的水样分离嗜酸氧化亚铁硫杆菌(Atf菌)和嗜酸氧化硫硫杆菌(Att)并进行纯化,然后将分离纯化后的Atf、Att菌菌株用于低品位磷矿中磷的浸出,并与经过磷矿驯化后的菌株进行浸磷效果对比和分析。研究结果表明:1)Att、Atf菌经过驯化后其生长活性有所提高,Att菌菌液平均pH比原菌有所降低,Atf菌经5~10 g/L磷矿粉驯化后菌液pH降低较明显;2)进行浸矿试验时,驯化菌株对磷矿粉有较强的适应能力,其pH下降较快,且30 d浸出率比原菌均有提高。其中Att菌在有磷培养基和无磷培养基中经过驯化后浸出率均有明显提高,最大提高了近11%;Atf菌在有磷培养基中经2~8 g/L磷矿粉驯化后浸出率提高显著,最大达28%,而在无磷培养基中经过10~15g/L磷矿粉驯化后浸磷效果最优,浸出率比原菌提高了1倍。     

氧化硫硫杆菌的培养特性及低品位磷矿浸出

从安徽某煤矿的酸性矿坑水中分离出能有效浸出低品位磷矿的氧化硫硫杆菌菌株,对其形态特征和培养特性进行了初步的研究,并通过研究不同固体培养基成分对氧化硫硫杆菌分离纯化的影响,确定了适宜的分离条件：采用双层平板,即上层为涂布氧化硫硫杆菌的Starkey固体培养基平板,下层为涂布异养菌（红酵母菌）的琼脂平板,可显著提高菌落密度并缩短检出时间。考查了培养基、表面活性剂等因素对所选育的氧化硫硫杆菌的浸磷效果的影响,通过初步试验浸磷率可达到48.41%。     

混合嗜酸硫杆菌浸出低品位磷矿的正交实验研究

以某矿酸性矿土中分离的嗜酸氧化亚铁硫杆菌和嗜酸氧化硫硫杆菌形成的混合菌为浸磷菌种、黄铁矿为能源物质、无磷无铁9K培养基为浸矿培养基,对混合菌浸出低品位磷矿石（w（P2O5）为22.8%）的浸磷条件进行了单因素优化和正交实验研究。结果表明,最优浸磷的适宜条件是,矿浆浓度为15 g/L,菌种体积浓度为15%,初始pH值为1.5,磷的浸出率为51.07%。     

微波诱变嗜酸氧化硫硫杆菌浸出低品位磷矿

从广西某含硫温泉中分离得到了嗜酸氧化硫硫杆菌菌株,经分离纯化与初步培养后进行浸出低品位磷矿实验.其后,利用微波诱变的方式对该细菌进行了诱变育种研究.结果表明:经分离纯化得到的Att菌对磷矿矿样有一定的浸出能力,但效果不佳;微波辐照能有效引起At t菌发生突变,使其生长活性及产酸能力均发生改变,与此对应的是诱变后的Att菌菌株对磷矿矿样的浸出能力较原菌株有了明显的改变;在不同诱变时间下得到菌株的浸矿能力有所不同,其中诱变10s的菌株对磷矿的浸出率高于其它菌株,浸矿20d后浸出率达到32.74%,比原菌株的浸出率提高了42%.     

非离子表面活性剂对细菌浸矿能力的影响

为了解非离子表面活性剂对细菌浸矿能力的影响,研究了吐温20、吐温80和乳化剂OP这三种非离子表面活性剂对氧化亚铁硫杆菌浸出多金属铜矿的影响,结果表明,三种表面活性剂对细菌浸出矿物均有一定促进作用,其中吐温20促进浸出效果最好,其最佳添加量为0.005%。     

胶硫钼矿型难选钼矿的微生物浸出试验研究

以一株嗜酸氧化亚铁硫杆菌(At.f菌)为浸矿菌种,对某胶硫钼矿型难选钼矿的浮选混合粗精矿进行了浸出试验研究,采用摇瓶浸出方法探讨了菌种驯化、浸出体系初始Fe~(2+)含量及矿浆含量等因素对Mo浸出的影响,并对浸出过程中溶液的pH值和氧化还原电位E_h的变化规律进行了研究.结果表明:生物浸出效果明显优于酸浸,且驯化后的At.f菌对Mo的浸出率显著提高;初始Fe~(2+)较高含量有利于At.f菌对Mo的浸出,在9K浸出体系下浸出83d后Mo的浸出率可达95.65%;矿浆含量对Mo的浸出速率影响明显,但对最终浸出率影响不大;浸出过程中E_h不断升高并维持在700mV以上,pH值逐渐减小到1.3,有利于Mo的浸出.     

不同因素影响嗜酸氧化亚铁硫杆菌浸出废弃PCB 中铜效果的研究进展

随着生物与环境交叉学科的不断发展,利用生物法浸出废弃印刷线路板(Printed Circuit Board,PCB)中的铜越来越引起重视。为了找出目前利用嗜酸氧化亚铁硫杆菌浸出废弃PCB中铜的最佳条件,综合讨论了对嗜酸氧化亚铁硫杆菌的生长及其浸出废弃PCB中铜效率的影响因素,并探讨了表面活性剂、电场、催化剂等外部因素对嗜酸氧化亚铁硫杆菌浸出废弃PCB中铜效果的影响。通过论述催化剂在嗜酸氧化亚铁硫杆菌浸矿中的促进作用,表明了能够促进嗜酸氧化亚铁硫杆菌生长的催化剂是存在的。由于铜在矿石和废弃PCB中的存在形态是不同的,研究开发适用于促进嗜酸氧化亚铁硫杆菌浸出废弃PCB中铜的催化剂将是未来的研究热点。     

应用表面活性剂进行低渗透砂岩铀矿床地浸采铀的实验研究

低渗透砂岩铀矿床的地浸开采是目前的一个技术难题.以新疆某铀矿为对象,利用搅拌浸出和柱浸实验研究了表面活性剂在低渗透铀矿地浸开采中的应用.实验中采用10 g/LH2SO4溶液作溶浸剂,并加入不同量的表面活性剂P.搅拌浸出实验结果表明,溶浸液中加入不同浓度的表面活性剂均可提高铀浸出率,在表面活性剂P的浓度为10 mg/L时其铀浸出率最高,达到92.6%.柱浸实验表明,加入10 mg/L表面活性剂P时矿石渗透系数可提高28.8%,铀的浸出率可提高32%而达到85.79%.表面活性剂降低溶浸液的表面张力,促进了铀的溶解和提高铀浸出率.低渗透砂岩铀矿床可以在溶浸液中加入适当的表面活性剂进行地浸开采.     

高磷赤铁矿两步法生物除磷实验研究

采用嗜酸氧化硫硫杆菌(At.t)直接浸出和两步法浸出,对鄂西高磷鲕状赤铁矿(铁品位43.50%,磷含量0.85%)进行生物除磷的实验研究。结果表明:矿浆浓度为2%时,At.t菌直接浸出除磷率为62.35%,且硫含量高达28.57%;采用两步法摇床培养At.t菌,24d菌液pH值接近0.8,磷含量可降至0.15%,硫含量为1.09%;采用自行设计制作的生物反应器培养At.t菌8d,菌液pH值接近0.98,分离菌液浸出原矿12h磷含量为0.18%。对磁选精矿进行的两步法浸出表明,当矿浆浓度为3%以下时菌液的除磷效果明显。     

Efficacy of chalcopyrite bioleaching using a pure and a mixed bacterium

To determine the efficacy of chalcopyrite bioleaching using pure cultures of Thiobacillus ferrooxidans or Thiobacillus thiooxidans and a mixed culture composed of Thiobacillus ferrooxidans and Thiobacillus thiooxidans, experiments were carried out in shake flasks with [Fe~(2 )] 4 g.L~(-1) and S 1 g.L~(-1) at pH=1.80, 130 r/min and 30℃. The tests showed that the copper extraction in a mixed culture composed of Thiobacillus ferrooxidans and Thiobacillus thiooxidans is higher than that in a pure culture. On the other hand, an important potential of Thiobacillus thiooxidans to leaching chalcopyrite was indicated. Thiobacillus thiooxidans can prevent jarosites accumulating on the substrate and allow further copper to dissolute through the action of ferric ion. The selection of the suitable pH in a leaching solution would be significant. Thiobacillus thiooxidans and Thiobacillus ferrooxidans play an important role in the bioleaching process. Finally, the mechanism and the reason for iron precipitation were also discussed in detail.     

Experimental Study of Preferential Solute Transportation During Dump Leaching

1 Introduction Low-grade mineral resources can effectively be recovered by dump leaching techniques. It is useful to extract metals from secondary sources such as dump- ing and waste disposal sites, tailing piles and so on. At present, dump leaching has widely been applied in mining of copper, gold, silver and uranium, because of its many virtues, such as simple and environment friendly techniques, lower investment and higher utilization rates[1–5]. Considerable economic and so- cial benefits…     

硫酸和氧化亚铁硫杆菌浸出低品位磷矿

研究了硫酸和氧化亚铁硫杆菌（Af．f．）浸出低品位磷矿过程中初始pH值和底物成分对磷的浸出率的影响．实验结果表明：在初始pH值为1．50～3．50时，硫酸和Af．f．都能有效提高细菌培养液中磷的浸出率，且当pH值为2．00、培养底物为混合矿时，Af．f．浸出磷矿中磷的浸出率最大，达到9．50％．     

Bioleaching of Nickel and Cobalt from Spent Nickel Metal Hydride Batteries by Acidithiobacilli spp

The Acidithiobacillus ferrooxidans(At.f) and Acidithiobacillus thiooxidans (At.t) were used in bio-dissolution experiments of heavy metals in spent MH/Ni batteries. The influences of the initial pH value,the concentration of electrode materials,the temperature and substrate concentration on the leaching rate of heavy metal Ni,Co have been investigated. The obtained results indicate that the efficiency of nickel extraction and cobalt extraction is dependent on all of the mentioned factors. Especially,the initial pH value and the temperature have more effect than other factors for these microorganisms. In addition,the results show that the optimal leaching rate of Ni and Co in the spent MH/Ni batteries reaches to 95.7% and 72.4% respectively after 20 days under the conditions of the initial pH value 1.0,concentration of electrode materials 1.0%,temperature 30 ℃ and substrate(sulfur) concentration 4.0 g·L-1.     

Enhancing the leaching effect of an ion-absorbed rare earth ore by ameliorating the seepage effect with sodium dodecyl sulfate surfactant

Ameliorating the problem of low leaching efficiency, long leaching period, and high agent consumption should be studied to efficiently exploit ion-absorbed rare earth ore resources. In this study, the surfactant sodium dodecyl sulfate (SDS) is used to enhance the leaching effect of an ion-absorbed rare earth ore by ameliorating the seepage effect for the first time. The effects of surfactant concentration, leaching agent dosage, solution flow velocity, and solution pH on the leaching rate were explored, and the mechanism of SDS was discussed. Under the optimum conditions, the addition of a small amount of SDS (mass fraction 0.04%) can increase the leaching rate by about 5%, shorten the leaching period, and reduce the consumption of the leaching agent. SDS significantly ameliorates the seepage effect of the ore body by reducing the surface tension of the leaching agent and ameliorating the wettability of the mineral surface. This effect is the main factor that improves the leaching efficiency. DFT (density functional theory) calculation results show that SDS can react with rare earth ions, which reduces the adsorption strength on clay mineral surfaces. Hence, rare earth ions are easily exchanged by ammonium ions, and mass transfer is enhanced.     

溶磷菌以木屑作载体的固定化研究

研究了在木屑载体固定化下生物膜反应器的曝气性能、嗜酸氧化硫硫杆菌(At.t)在木屑填料下固定化效果,以及接种量等因素的影响。结果表明:1)木屑作为固定化材料,能够提供稳定的生存环境,嗜酸氧化硫硫杆菌具有良好的生物活性;2)木屑固定化At.t产酸能力强,缩短了培养周期;3)At.t接种量12.5%、硫磺粉用量1%(w/v)、培养(8 d)、生物膜反应器中溶解氧维持6 mg/L以上时,反应系统pH=0.964,H+浓度0.108 7 mol/L,电导率为45.2 ms/cm。