An effective approach for improving flotation recovery of molybdenite fines from a finely-disseminated molybdenum ore

An effective flotation approach is proposed for improving the recovery of molybdenite fines from a finely-disseminated molybdenum ore. To maximize the flotation recovery of molybdenum, process mineralogy of raw ore, contrast tests, optimization of operation conditions and particle size analysis were systematically investigated. Process mineralogy suggests that in the raw ore, 61.63% of molybdenite particles distribute in the 〈20 pm size fraction, and intergrow with muscovite and pyrite as the contained and disseminated type. Contrast tests indicate that conventional flotation responds to poor collection efficiency for particles less than 25 pm. Oil agglomerate flotation （OAF） process demonstrates an obvious superiority in improving the flotation recovery of molybdenite fines. Furthermore, the flotation results of OAF process reveal that the dosage of transformer oil plays a critical role on the average size of collected mineral particles （d（0）, agglomerates （d^0） and the molybdenum recovery. In addition, industrial tests illustrate that compared with the Mo-S bulk flotation approach, OAF process not only increases Mo recovery and grade of molybdenum concentrate by 22.75% and 17.47% respectively, but also achieves a sulfur concentrate with a superior grade of 38.92%.

Experimental Investigation of Dust Deposit within Ceramic Filter Medium during Filtration-Cleaning Cycles

The penetration and deposit of particles within the medium is thought to be one reason that the residual pressure drop of the rigid ceramic filter increase with cycle number.In this study,the change in the microstructure of a single layer ceramic filter candle during filtration-cleaning cycle was observed by scanning electron microscope(SEM) and the resistance property of the filter was monitored accordingly.The experimental results show that there exists a serious dust deposit within the filter medium,especially at the surface region.This should be responsible for the decrease of the filter permeability.The deposit law of dust in the filter medium during filtration-cleaning cycle was then studied by measuring the deposit depth,the deposit amount,the particles distribution within the medium,the size distribution of deposited particles,and so on.Particles migration and fine particles penetration were found to be the main reasons,for which dust deposit within the filter medium became aggravated with cycle number.Based on a differential form of Ergun equation,an expression for the pressure drop of a used ceramic filter was developed with a good agreement with experimental results.Then,the effect of dust deposit on the residual pressure drop was studied at the different face velocities and dust sizes.It was found that face velocity and dust size significantly influence dust deposit within filter medium,and then the operation performance of the filter.

Comparative Research on Payment Protocols SSL and SET in Electronic Commerce

The security of electronic payment is one discusses the secure mechanism and transaction process of the key problems in electronic commerce. This paper of the two electronic payment protocols SSL and SET, and presents the differences between them on security, function and practicality. SSL takes an active role in current electronic payment. With high security and perfect specifications, however, SET isn＇t widely used at present because of its complexity. But it will change in the future.

Online Shopping A Block to E-commerce

The rapid growth oflnternet technology development has made Chinese consumers search for products over the Internet and purchase products or services from Web-retailers. E-commerce is growing to represent an increasing share of overall sale avenue, and online shopping is expected to continue growing for foreseeable future. As such, it is vital to identify the performance of shopping online and investigate the effects that shopping online has on e-commerce.The methods used in this study are consulting some authentic materials and looking into some cases in point. It is found that shopping online has so many disadvantages, such as credit crisis, the insecurity of e-bank, express problem, a series of relevant law problems, limited payment options and so on.Because of these limitations, shopping online has interfered with e-commerce. Overall, shopping online is more or less a bar to e-commerce.

如何破解农村基层工作两难困境——“千万别让他们知道”之三问

我曾在一个帮扶干部的日志中看到了这样一则内容,大概意思是说在自己所驻的贫困村有一家特困户,经过政策支持终于把破旧的房子改建好了,不再风餐露宿了,但是日常生活还是举步维艰。快过年了,这名帮扶干部就多方争取、自己筹集,得来了一笔款子,过年前和一名村干部一起给这家人送了过去,好让他们一家过上相对宽裕的春节。

Identification of aeolian loess deposits on the Indo-Gangetic Plain(India)and their significance

Aeolian loess deposits contain abundant information about the evolution of the paleoenvironment.For example,paleoclimate changes recorded in Chinese loess area obtained significant achievement in the past few decades.Compared to Chinese loess,research on Indian loess is lacking.Currently,most studies focus on the Kashmir area located in the southern Himalayas,and studies on other areas are rare.However,field observations demonstrate that the sediments around the New Delhi-Agra-Jaipur Plain are similar to Chinese loess-paleosol sequences.For example,the boundary between two strata is transitional and without horizontal bedding.Moreover,obvious pedogenic horizons developed among sediment sequences,probably indicating unrecognised aeolian deposits in the Indo-Gangetic Plain(IGP).To confirm this,pilot samples were obtained from the IGP and detailed indoor measurements conducted.The results indicate that the distribution patterns of particle size and rare earth elements(REE) of the pilot samples are similar to Chinese loess.Furthermore,the scanning electronic microscopy(SEM) images of pilot samples show obvious conchoidal fractures,dash-shaped concavities,and abundant small pits that usually form through mechanical impact.These are typical characteristics of aeolian particles.In addition,environmental and rock magnetic measurements indicate that the dominant magnetic minerals in the pilot samples are magnetite and maghemite,and that they likely contain small amounts of hematite.Furthermore,conventional magnetic parameters are comparable with Chinese loess.Based on this,aeolian loess deposits are widely distributed in the IGP,which may have promoted the development of Indian farming and contributed towards the prosperity of ancient Indian civilisation.This study also provides a new and valuable record for the research on paleoclimate changes in the study area in the future.