The Significance of Flotation Frothers Chemical Structure and Fundamental Properties: A Review

Froth flotation is a separation process widely used in the mineral processing industry that depends on differences in particle surface properties to separate valuable materials from undesired gangue. In froth flotation, an addition of a surfactant, acting as frother is usually needed. The basic function of the frother is to produce a swarm of air bubbles, which remain sufficiently stable for the hydrophobic mineral particles to be captured by them. This Paper presents a combination method of a foaming agent-surfactant composition with desirable selectivity and foaming properties. Wherein 1-butanol (C4H10O) is a main flotation foaming agent, which decides bubble sizes in a collecting area;and tetraethylene glycol (C8H18O5) is an auxiliary foaming agent, which affects a rising velocity of the bubbles in the collecting area and a foaming capability in a selected area. Set concentrations of the two components are respectively 60 ppm for the 1-butanol and 120 ppm for the tetraethylene glycol. An addition sequence is the 1-butanol followed by the tetraethylene glycol. The dual advantages of the selectivity and foaming properties of the foaming agent-surfactant composition in the present disclosure are verified through a series of tests, and desirable yields can be obtained in practice.

Application of NSR-AISC Method in Reserve Estimation and Technical Economic Evaluation of Low-Grade Polymetallic Deposits: Taking a Low-Grade Copper-Molybdenum Mine in Guangdong Province as an Example

The development and utilization of low-grade polymetallic deposits with strategic mineral resources is one of the important measures to alleviate the current high dependence on strategic mineral resources in China. However, domestic mining enterprises and most mining consulting and design institutes usually use general industrial indicators to carry out reserve estimation and technical and economic feasibility studies on low-grade polymetallic deposits, which cannot truly reflect the economic value of such deposits. The article expounds on the definitions of net return value (NSR) and on-site total maintenance cost (AISC) of common ore smelters in the evaluation of overseas mineral resources. Taking a low-grade polymetallic copper-molybdenum mine in Guangdong Province as an example, comparing the research results showed the NSR-AISC method and the general industrial index method in low-grade polymetallic deposit. There are huge differences in the results of reserve estimation;through the further introduction of Taylor’s formula and the research results on the relationship between investment intensity and production scale, a more reasonable mine life and investment scale are recommended, and a more in-depth comparative study has been carried out in the dimension of technical and economic indicators. Based on the comparative study of the above two methods in reserve estimation and the evaluation results of technical and economic indicators, the author believes that the NSR-AISC method can better reflect the true value of low-grade polymetallic ore projects, and should be popularized and applied in resource evaluation and development practice. This article further describes the application status of the NSR-AISC method for reserve estimation and the evaluation of technical economic indicators, and suggests the main points that should be paid attention to in the use of the NSR-AISC method.

Recent Technological Innovation for the New Generation of CRIST Sensors—A Practical Approach in China’s Largest Underground Nonferrous Mine

Located in Shangri-La county, Yunnan Province, China’s biggest underground nonferrous mine Pulang Copper Mine is under construction. To date, the defined copper reserves at the Pulang Copper Mine are 4.8 million tonnes of copper and an average grade of 0.34%. The mineralized zone is 2300 m long, 600 - 800 m wide, and 1000 m high in a dome shape. The first-stage mining and processing capacity is 12.5 million tonnes of ore per year. By geotechnical investigation, ore haulage is adopted via a drift and ore pass development system. From mineralogical analysis, a majority of the Pulang copper ore body is classified as a type III rock, which is generally considered to be suitable for block-caving methods. As an update to the traditional mine-to-mill approach, a cave-to-mill integrated production concept is then introduced. This is essentially the integration of underground mine production scheduling and monitoring with surface mineral processing management based on fragment size and geometallurgical ore characteristics. Several unique challenges experienced during the project design and construction, as well as a number of features aimed at mitigating these problems, are also discussed in this paper.

Elimination of phosphorus vaporizing from molten silicon at finite reduced pressure

Elimination of phosphorus vaporizing from silicon was investigated. Si-P alloy made from electronic grade silicon was used. All the samples were analyzed by GD-MS. Theory calculation determines that phosphorus evaporates from molten silicon as gas species P and P2 at a finite reduced pressure. The experimental results show that phosphorus mass fraction can be decreased from 0.046% （460ppmw） to around 0.001% （10ppmw） under the condition of temperature 1 873 K, chamber pressure 0.6-0.8 Pa, holding time 1 h. Both experimental data and calculation results agree that at high phosphorus concentration, phosphorus removal is quite dependent on high chamber pressure while it becomes independent on low chamber pressure. The reason is that phosphorus evaporates from molten silicon as gas species P2 at a relatively high phosphorus concentration, while gas species P will be dominated in its vapour at low phosphorus content.

Non-contact intelligent sensor for recognizing transparent and naked-eye indistinguishable materials based on ferroelectric BiFeO_(3)thin films

At present,the research on ferroelectric photovoltaic materials mainly focuses on photoelectric detection.In the context of the rapid development of the Internet of Things(IoT),it is particularly important to use smaller thin-film devices as sensors.In this work,an indium tin oxide/bismuth ferrite(BFO)/lanthanum nickelate device has been fabricated on an F-doped tin oxide glass substrate using the sol–gel method.The sensor can continuously output photoelectric signals with little environmental impact.Compared to other types of sensors,this photoelectric sensor has an ultra-low response time of 1.25 ms and ultra-high sensitivity.Furthermore,a material recognition system based on a BFO sensor is developed.It can effectively identify eight kinds of materials that are difficult for human eyes to distinguish.This provides new ideas and methods for developing the IoT in material identification.

A new type of rare earth elements deposit in weathering crust of Permian basalt in western Guizhou, NW China

A new type of rare earth elements （REEs） deposit was discovered from the gaolinite mudstone in the weathering crust of Permian basalt, Bijie region, western Guizhou, China. It contained ∑RE2O3 0.065%-1.086%. This type of REEs deposit was widely distributed with steady horizon and thickness of 3-4 m. The ore-bearing weathering crust （kaolinite） of the three discovered REEs deposits belonged to the third episode of the Emeishan basalt eruption. The new type of REEs deposit was suggested that basalt （tuff） weathering could lead to the enrichment of the rare earth elements. Therefore, it is of important economic significance to explore REEs deposits in the weathering crust of basalt （tuffs） in Yunnan, Guizhou, and Sichuan Provinces.

Abstinence Following a Motivation-Skill-Desensitization-Mental Energy Intervention for Heroin Dependence: A Three-year Follow-up Result of a Randomized Controlled Trial

The high rate of relapse among heroin users remains a significant public concern in China. In the present study, we utilized a Motivation-Skill-Desensitization-Mental Energy (MSDE) intervention and evaluated its effects on abstinence and mental health. Eighty-nine male heroin users in a drug rehabilitation center were enrolled in the study. The participants in the MSDE intervention group (n=46) received MSDE intervention, which included motivational interviewing, coping skills training, eye movement desensitization and reprocessing, and mindfulness-based psychotherapy. The participants in the control group (h=43) received a series of lectures on skills training. A significant increase in Contemplation Ladder score (P<0.001) and decreases in scores on the Obsessive Compulsive Drug Use Scale (P<0.001), Beck Depression Inventory (P<0.001), and Aggression Questionnaire (P=O.O33) were found immediately after intervention. Compared to the control group, the MSDE intervention group reported significantly higher abstinence rates (P=0.027) and retention rates (P<0.001) at follow-up. Overall, the MSDE intervention, which uses a combined strategy for relapse prevention, could be a promising approach for preventing relapse among heroin users in China.

Microstructural characteristics and mechanical properties of bobbin-tool friction stir welded 2024–T3 aluminum alloy

Cold-rolled 2024-T3 sheet alloy was subjected to bobbin-tool friction stir welding （BTFSW）. The microstructural characteristics and mechanical properties of the nugget zone in the as-welded state were investigated. The results show that the equiaxed grain size of BTFSW 2024-T3 alloy decreases from 7.6 to 2.8 μm as the welding speed is increased from 80 to 120 mm/min; in addition, fine grains are generated in the nugget zone and the size distribution is non-uniform. All A12CuMg （S＇） precipitates dissolve into the A1 matrix, whereas Mn-rich phases confirmed as T phases （Al20CuEMn3, A16Mn, or AlaMn） remain unchanged. The optimized parameters for BTFSW are veri- fied as the rotation speed of 350 r/min and the travel speed of 100 mm/min. The variations in precipitation and dislocation play more impor- tant roles than grain size in the nugget zone with respect to influencing the mechanical properties during the BTFSW process. After the BTFSW process, the fracture mode of base material 2024-T3 alloy transforms from ductile rupture to ductile-brittle mixed fi＇acture.

Interaction between climate and management on beta diversity components of vegetation in relation to soil properties in arid and semi-arid oak forests, Iran

This study aimed to investigate the interaction between regions with different climatic conditions(arid vs. semi-arid) and management(protected vs. unprotected) on the turnover and nestedness of vegetation in relation to physical, chemical and biological properties of soils in the Ilam Province of Iran. In each of the two regions, we sampled 8 sites(4 managed and 4 unmanaged sites) within each of which we established 4 circular plots(1000 m^2) that were used to investigate woody species, while two micro-plots(1 m×1 m) were established in each 1000-m^2 plot to analyze herbaceous species. In each sample unit, we also extracted three soil samples(0–20 cm depth) for measuring soil properties. The results indicated that the interaction between region and conservational management significantly affected the percent of canopy cover of Persian oak(Quercus brantii Linddl), soil respiration, substrate-induced respiration, as well as beta and gamma diversities and turnover of plant species. The percent of oak canopy cover was positively correlated with soil silt, electrical conductivity, available potassium, and alpha diversity, whereas it was negatively correlated with plant turnover. In addition, plant turnover was positively related to available phosphorus, while nestedness of species was positively related to organic carbon and total nitrogen. According to these results, we concluded that physical, chemical, and biological characteristics of limited ecological niche generally influenced plant diversity. Also, this study demonstrated the major contribution of the beta diversity on gamma diversity, especially in semi-arid region, because of the higher heterogeneity of vegetation in this area.

Multi-objective optimization for draft scheduling of hot strip mill

A multi-objective optimization model for draft scheduling of hot strip mill was presented, rolling power minimizing, rolling force ratio distribution and good strip shape as the objective functions. A multi-objective differential evolution algorithm based on decomposition （MODE/D）. The two-objective and three-objective optimization experiments were performed respectively to demonstrate the optimal solutions of trade-off. The simulation results show that MODE/D can obtain a good Pareto-optimal front, which suggests a series of alternative solutions to draft scheduling. The extreme Pareto solutions are found feasible and the centres of the Pareto fronts give a good compromise. The conflict exists between each two ones of three objectives. The final optimal solution is selected from the Pareto-optimal front by the importance of objectives, and it can achieve a better performance in all objective dimensions than the empirical solutions. Finally, the practical application cases confirm the feasibility of the multi-objective approach, and the optimal solutions can gain a better rolling stability than the empirical solutions, and strip flatness decreases from （0± 63） IU to （0±45） IU in industrial production.

Modeling hot strip rolling process under framework of generalized additive model

This research develops a new mathematical modeling method by combining industrial big data and process mechanism analysis under the framework of generalized additive models(GAM)to generate a practical model with generalization and precision.Specifically,the proposed modeling method includes the following steps.Firstly,the influence factors are screened using mechanism knowledge and data-mining methods.Secondly,the unary GAM without interactions including cleaning the data,building the sub-models,and verifying the sub-models.Subsequently,the interactions between the various factors are explored,and the binary GAM with interactions is constructed.The relationships among the sub-models are analyzed,and the integrated model is built.Finally,based on the proposed modeling method,two prediction models of mechanical property and deformation resistance for hot-rolled strips are established.Industrial actual data verification demonstrates that the new models have good prediction precision,and the mean absolute percentage errors of tensile strength,yield strength and deformation resistance are 2.54%,3.34%and 6.53%,respectively.And experimental results suggest that the proposed method offers a new approach to industrial process modeling.

Transition of Thalassaemia and Friedreich ataxia from fatal to chronic diseases

Thalassaemia major(TM) and Friedreich's ataxia(FA) are autosomal recessive inherited diseases related to the proteins haemoglobin and frataxin respectively. In both diseases abnormalities in iron metabolism is the main cause of iron toxicity leading to increased morbidity and mortality. Major efforts are directed towards the prevention of these diseases and also in their treatment using iron chelation therapy. Both TM and FA are endemic in Cyprus, where the frequency per total population of asymptomatic heterozygote carriers and patients is the highest worldwide. Cyprus has been a pioneering nation in preventing and nearly eliminating the birth of TM and FA patients by introducing an organized health structure, including prenatal and antenatal diagnosis. Effective iron chelation therapy, improved diagnostic methods and transfusion techniques as well as supportive therapy from other clinical specializations have improved the survival and quality of life of TM patients.Despite the tiresome clinical management regimes many TM patients are successful in their professional lives, have families with children and some are now living well into their fifties. The introduction of deferiprone led to the elimination of cardiac failure induced by iron overload toxicity, which was the major cause of mortality in TM. Effective combinations of deferiprone with deferoxamine in TM patients caused the fall of body iron to normal physiological ranges. In FA different mechanisms of iron metabolism and toxicity apply to that of TM, which can be targeted with specific iron chelation protocols. Preliminary findings from the introduction of deferiprone in FA patients have increased the hopes for improved and effective therapy in this untreatable condition. New and personalised treatments are proposed in TM and FA. Overall, advances in treatments and in particular of chelation therapy using deferiprone are transforming TM and FA from fatal to chronic conditions. The paradigm of Cyprus in the prevention and treatment of TM can be used for application worldwide.

Cultural Nourishment for the Development of Chinese Medicine

Medicine,especially traditional Chinese medicine,is by no means a single level of knowledge system and operational skills,blit is frill of humanistic color,encompassing natural science and social science,medical theory and traditional culture.Traditional Chinese medicine is rooted in the splendid traditional culture of China,and its theoretical exploration methods and explanations are based on the historical and colorful traditional Chinese culture.This article will give advice on the irrigation and nourishment of traditional culture.

Application of Over-Winding and Over-Falling Buffer Unit in Coal Mines of Datong Coal Group Company

Dynamic force of BS buffer unit in the enwinding hoisting system is calculated, and the buffer unit is in- stalled and tested. The result shows that this buffer unit is accurate in its regulated braking force and convenient in ad- justment and restoration. It can be repeatedly used as a bumper for both over-winding and over-falling without replacing any parts, providing an applicable device for safety operation in coal mining.

Farm-Scale Applicability of Three Covers (Peat, Polystyrene Balls and Synthetic Sheet Roof) to Reduce Ammonia Emissions from Pig Slurry Storage

Covering the slurry pit has been shown to be one of the best ways to reduce ammonia emissions (NH3) during manure management. Yet, few studies have been conducted at farm scale. We studied the feasibility of three cover materials (peat, polystyrene balls and synthetic sheet roof) to reduce ammonia (NH3) emissions during on-farm storage of pig slurry. The impact on greenhouse gas emissions, methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2) of covering the slurry pit was also evaluated. Simultaneous field experiments were carried out using two similar pits at a farm with peat and polystyrene ball covers, which allowed direct comparison of the feasibility of the two covers to reduce gas emissions (measured using the dynamic chamber technique). Emissions from the third option (using a synthetic sheet roof) were estimated by measuring the concentrations in the headspace under the cover and the air leakage from the cover with a tracer gas (CO2). Results showed that the polystyrene balls cover reduced emissions of NH3 during storage by up to 80% whatever the season, but increased potential greenhouse gas emissions by 20% in summer. No consistent reduction was achieved with the peat cover even though some individual results seemed to indicate up to 25% reduction in ammonia emissions;moreover, there was a 30% increase in CH4 and CO2 emissions during the storage period. The use of a synthetic sheet roof enabled up to 90% reduction in NH3, CH4 and CO2 emissions whatever the season.

Investigation of a Network Failure Problem with a Significant Path, from the Perspective of Crisis Management

The objective of this study is to investigate a network failure problem with a significant path, emerging from the context of crisis management, such as in the case of natural disasters. For a given tree with m failed edges, we assume that we have sufficient resources to recover k edges of the m edges. Each node has a positive weight. In this situation, we consider which k edges should be fixed in order to maximize the sum of the weights of the nodes reachable from the significant path. In this paper, we formulate such a problem as a combinatorial problem. Further, we show that a part of our problem may be solved by translating it into the terms of the so-called tree knapsack problem.

Prevalence and intensity of soil-transmitted helminth infections among school-age children in the Cagayan Valley, the Philippines

Objective:To identify the prevalence of soil-transmitted helminthiasis(STH)among school-age children in the Cagayan Valley,the Philippines,assess their level of awareness on the disease,and determine predisposing factors of the disease.Methods:A total of 478 GradesⅢ-Ⅴschool-age children in Pamplona and Sanchez-Mira School Districts in the Cagayan Valley answered the questionnaire assessing their knowledge,attitude,and practices on STH,subjected to anthropometric measurements,and provided faecal samples for parasitologic assessment(direct smear,Kato-Katz,and formol-ether concentration techniques).Results:The participants of the study,with 55.86%females,were 8 to 14 years old.Their nutritional status was assessed‘normal’(84.31%),‘severely wasted’(6.49%),‘wasted’(5.23%),‘overweight’(2.72%),and‘obese’(1.26%).The prevalence of infection with at least 1 STH species was 25.99%in Pamplona and 19.40%in SanchezMira.Overall,the prevalence of heavy intensity was 7.11%for Ascaris lumbricoides and 1.67%for Trichuris trichiura.All hookworm infections had light intensities.The majority of the school-age children had a low score in the KAP test.In knowledge of STH,‘stunted growth as a symptom of infection’was associated with a lower risk of Ascaris lumbricoides infection(OR 0.448;95%CI 0.212,0.945;P=0.035)while‘playing with soil as a mode of transmission’was associated with an increased risk of Ascaris lumbricoides infection(OR 2.067;95%CI 1.014,4.212;P=0.046).In attitude towards STH,‘I think I have intestinal worm now’was associated with a higher risk of Ascaris lumbricoides infection(OR 1.681;95%CI 1.061,2.662;P=0.027).Conclusions:The prevalence rate of Ascaris lumbricoides among the school-age children in the Cagayan Valley shows the need to further intensify intervention in the area to meet the threshold set by the World Health Organization.The identified predictors of infection,which concerns the school-age children’s knowledge and attitude toward STH,can be used in augmenting intervention programs in the future.

Vibration analysis of foam plates based on cell volume distribution

In this paper, vibration analysis of irregular-closed-cell foam plates is per- formed. A cell volume distribution coefficient is introduced to modify the original Gibson- Ashby equations of effective Young＇s modulus of foam materials. A Burr distribution is imported to describe the cell volume distribution situation. Three Burr distribution pa- rameters are obtained and related to the cell volume range and the diversity. Based on the plate theory and the effective modulus theory, the natural frequency of foam plates is calculated with the change of the cell volume distribution parameters. The relationship between the frequencies and the cell volumes are derived. The scale factor of the average cell size is introduced and proved to be an important factor to the performance of the foam plate. The result is shown by the existing theory of size effects. It is determined that the cell volume distribution has an impact on the natural frequency of the plate structure based on the cell volume range, the diversity, and the average size, and the impact can lead to optimization of the synthesis procedure.

Photocatalytic Activity of Nanosized TiO_2 Enhanced by co-doping with Fe^(3+) and Nd^(3+) Ions

In this study, nanosized TiO2 co-doped with Fe3+ and Nd3+ ions was synthesized via a sol-gel method. The metallic ion doped TiO2 was thoroughly characterized with XRD and UV-vis, and the photocatalytic activity was evaluated by degrading methylene blue (MB) solution. The results indicated that TiO2 crystalline size was reduced and phase transformation of anatase to rutile was suppressed as the content of doped Nd3+ ion increased in the co-doped TiO2. The UV-vis spectra of co-doped TiO2 seemed to simply overlay two spectra of single metal doped TiO2, and had significantly increased absorbance in the ranges of 400～500 nm, 565～600 nm and 730～765 nm as compared to pure TiO2. The photocatalytic activity of co-doped TiO2 was obviously enhanced, and raised about 30% compared to that of pure TiO2 as doped Nd3+ content was 0.15% and Fe3+ content was 0.05%, respectively. The enhanced catalytic activity was attributed to a synergistic effect of two doped ions, where doped Fe3+ ion inhibited the recombination of photogenerated electron and hole, and Nd3+ ion brought more surface carboxyl to promote the degradation reaction.

Reaction Kinetics of LiOH·H_2O and CO_2 Improved with Composite Silica Gel of Lanthanum Chloride

Reaction kinetics of LiOH·H2O and CO2 within a closed system were studied under the adsorption of water vapor by composite silica gel of lanthanum chloride. At the reaction temperature of 273～323 K and initial CO2 pressures of 40～100 kPa, reaction kinetics obeyed the Erofeev model. The reaction rate decreased slightly while the initial CO2 pressure reduced. When the reaction occurred at 273～299 K, the reaction rate was so low that it was almost independent of the reaction temperature. However, as the temperature rose up to 300～323 K, LiOH·H2O dehydrated its crystal water, and both the dehydrated and reaction-generated water were evaporated from solid reactant. For the dehydration rate increased, the reaction rate also increased as the reaction temperature rose. While the temperature was higher than 323 K, the reaction apparent activation energy of LiOH·H2O and CO2, was higher than 52.5 kJ·mol-1 and close to 61.4 kJ·mol-1 of the LiOH·H2O dehydrated enthalpy variable at 298 K, in which anhydrous LiOH was the major reactant and showed the reaction characteristics of LiOH crystals.