Alkyl dimethyl betaine activates the low-temperature collection capacity of sodium oleate for scheelite

The impact of alkyl dimethyl betaine (ADB) on the collection capacity of sodium oleate (NaOl) at low temperatures was evaluated using flotation tests at various scales. The low-temperature synergistic mechanism of ADB and NaOl was explored by infrared spectroscopy, X-ray photoelectron spectroscopy, surface tension measurement, foam performance test, and flotation reagent size measurement.The flotation tests revealed that the collector mixed with octadecyl dimethyl betaine (ODB) and NaOl in a mass ratio of 4:96 exhibited the highest collection capacity. The combined collector could increase the scheelite recovery by 3.48% at low temperatures of 8–12℃. This is particularly relevant in the Luanchuan area, which has the largest scheelite concentrate output in China. The results confirmed that ODB enhanced the collection capability of NaOl by improving the dispersion and foaming performance. Betaine can be introduced as an additive to NaOl to improve the recovery of scheelite at low temperatures.

Application of EDTMPS as a novel calcite depressant in scheelite flotation

In this study, the innovative use of ethylenediamine tetramethylene phosphonic sodium(EDTMPS) as a calcite depressant in scheelite flotation was investigated by flotation experiments, and its selective depression mechanism was revealed by contact angle measurement, FTIR analysis, Zeta potential test and XPS analysis. The flotation experiment results showed that scheelite and calcite could be efficiently separated under the following conditions: pulp p H=9.5, Na OL concentration of 1.5×10^(-4)mol/L, EDTMPS concentration of 3.0×10^(-5)mol/L, a scheelite concentrate with WO3grade of 65.49%, recovery of 83.29%and separation efficiency of 65.29% could be obtained from the artificially mixed minerals. The analysis results of mineral surface properties demonstrated that EDTMPS was strongly adsorbed onto the calcite surface through the reaction between the phosphonate group and the calcium ions, which hindered Na OL adsorption and increased the hydrophilicity of calcite. However, EDTMPS had weak adsorption strength on the scheelite surface, which didn’t affect further adsorption of Na OL, hence, the scheelite remained hydrophobic. Consequently, the selective adsorption of EDTMPS on the two minerals’ surfaces increased a difference in wettability and thus enabling them to be separated by flotation. Finally, the mechanism model of this flotation separation process was established.

Effect of depressants on flotation separation of magnesite from dolomite and calcite

The flotation separation of magnesite from calcium-containing minerals has always been a difficult subject in minerals processing.This work studied the inhibition effects of carboxymethyl cellulose(CMC),sodium lignosulphonate,polyaspartic acid(PASP)and sodium silicate on flotation behaviors of magnesite,dolomite and calcite,providing guidance for the development of reagents in magnesite flotation.The micro-flotation results showed that among these four depressants,sodium silicate presented the strongest selectivity due to the highest recovery difference,and the flotation separation of magnesite from dolomite and calcite could be achieved by using sodium silicate as the depressant.Contact angle measurement indicated that the addition of sodium silicate caused the largest differences in surface wettability of the three minerals,which was in line with micro-flotation tests.Furthermore,zeta potential test,the Fourier transform infrared(FT-IR)spectroscopy and atomic force microscope(AFM)imaging were used to reveal the inhibition mechanism of sodium silicate.The results indicated that the dominated component SiO(OH)3
of sodium silicate could adsorb on minerals surfaces,and the adsorption of sodium silicate hardly affected the adsorption of NaOL on magnesite surface,but caused the reduction of NaOL adsorption on dolomite and calcite surfaces,thereby increasing the flotation selectivity.

Key technologies and development trends for efficient flotation recovery of lepidolite

Lepidolite is an essential lithium resource with diverse applications in lithium-ion batteries,ceramics,glass,and other industrial sectors.Efficient flotation of lepidolite is crucial for the extraction and recycling of lithium resources,holding significant economic and environmental importance.This review provides a comprehensive overview of the research progress on the processes,reagents,and mechanistic understanding of lepidolite flotation,grounded in the fundamental properties of lepidolite and its major gangue minerals.The article critically analyzes the current lepidolite flotation technologies and highlights the research focus on overcoming the challenge of significant fine-grained lepidolite losses during the flotation process.Through synthesis and discussion,the review also presents an outlook on the future development of lepidolite flotation technology.This comprehensive review serves as a valuable reference for advancing lepidolite flotation techniques,providing insights that enhance the efficient recovery and utilization of lithium resources,as well as the development of the new energy industry.

A novel approach to with a preparing ultra-lightweight ceramsite large amount of fly ash

The disposal of fly ash has become a serious problem in China due to its rapid increase in volume in recent years.The most common method of fly ash disposal is solidification-stabilization-landfill,and the most common reuse is low-value-added building materials.A novel processing method for preparing ultra-lightweight ceramsite with fly ash was developed.The results show that the optimal parameters for preparation of ultra-lightweight ceramsite are as follows:mass ratio of fly ash:kaolin:diatomite=80:15:5,preheating temperature of 800℃,preheating time of 5 min,sintering temperatiire of 1220℃,and sintering time of 10 min.The expansion agent is perlite,at 10 wt.% addition.Finally,a ceramsite with bulk density of 340 kg/m3,particle density of 0.68 g/cm3,and cylinder compressive strength of 1.02 MPa was obtained.Because of its low density and high porosity,ultra-lightweight ceramsite has excellent thermal insulation performance,and its strength is generally low,so it is usually used in the production of thermal insulation concrete and its products.The formation of a liquid-phase component on the surface,and generation of a gas phase inside ceramsite during the sintering process,make it possible to control the production of the suitable liquid phase and gas in this system,resulting in an optimization of the expansion behavior and microstructure of ceramsite.These characteristics show the feasibility of industrial applications of fly ash for the production of ultralightweight ceramsite,which could not only produce economic benefits,but also conserve land resources and protect the environment.

Uncovering the evolution of tin use in the United States and its implications

Tin is of key importance to daily life and national security;it is considered an essential industrial metal.The United States(US)is the world’s largest economy and consumer of natural resources.Therefore,the analysis of historical tin use in the US is helpful for understanding future tin use trends in the world as a whole and in developing countries.Time series analysis,regression analysis with GDP or GDP/capita,and historical data fitted with logistic and Gompertz models are employed in this study.Historical tin use in the US shows three stages-increase-constant-decrease,as GDP per capita has increased.Tin use in the US is negatively correlated with the GDP value added by the manufacturing sector,while the use of tin worldwide and in China continues to increase along with the GDP value added by the manufacturing sector.Although a sigmoid curve can fit the US tin use data well,that use is not directly related to the limited tin reserves or resources.Rather,policies,economic restructuring,substitutions,new end-use markets,etc.have played key roles in the changing tin use patterns.This work contributes to understanding future tin use at both the global and national levels:tin use will continue to increase with GDP at the global level,but use patterns of tin at the national level can be changed through human intervention.