A novel molybdenite depressant for efficient selective flotation separation of chalcopyrite and molybdenite

A novel small molecule depressant(M-DEP)was used to separate chalcopyrite and molybdenite via flotation.The results showed that M-DEP had an excellent selective depression on molybdenite,while had little effect on the flotation of chalcopyrite.The adsorption capacity of M-DEP on the surface of molybdenite was greater than that on chalcopyrite surface.The adsorption of M-DEP reduced the floatability of molybdenite and had less effect on the floatability of chalcopyrite,which was due to its different adsorption modes on the surface of the two minerals.Furthermore,the interaction between chalcopyrite and M-DEP was mainly chemical interaction,and almost all of the adsorbed M-DEP molecules were removed and replaced by sodium butyl xanthate(SBX).By contrast,hydrophobic interaction was the main way in which M-DEP was adsorbed on the molybdenite surface with little chemical interaction,which was less interfered by SBX addition.Therefore,M-DEP had a super selective depression on molybdenite.The study provided a novel depressant and approach for the deep separation of chalcopyrite and molybdenite via flotation.

Advances in depressants for flotation separation of Cu–Fe sulfide minerals at low alkalinity:A critical review

The flotation separation of Cu–Fe sulfide minerals at low alkalinity can be achieved using selective depressants.In the flotation system of Cu–Fe sulfide minerals,depressants usually preferentially interact with the pyrite surface to render the mineral surface hydrophilic and hinder the adsorption of the collector.This review summarizes the advances in depressants for the flotation separation of Cu–Fe sulfide minerals at low alkalinity.These advances include use of inorganic depressants (oxidants and sulfur–oxygen compounds),natural polysaccharides (starch,dextrin,konjac glucomannan,and galactomannan),modified polymers (carboxymethyl cellulose,polyacrylamide,lignosulfonate,and tricarboxylate sodium starch),organic acids (polyglutamic acid,sodium humate,tannic acid,pyrogallic acid,salicylic acid,and lactic acid),sodium dimethyl dithiocarbamate,and diethylenetriamine.The potential application of specific inorganic and organic depressants in the flotation separation of Cu–Fe sulfide minerals at low alkalinity is reviewed.The advances in the use of organic depressants with respect to the flotation separation of Cu–Fe sulfide minerals are comprehensively detailed.Additionally,the depression performances and mechanisms of different types of organic depressants on mineral surfaces are summarized.Finally,several perspectives on depressants vis-à-vis flotation separation of Cu–Fe sulfide minerals at low alkalinity are proposed.

Flotation separation of scheelite from calcite using luteolin as a novel depressant

This paper proposes luteolin(LUT)as a novel depressant for the flotation-based separation of scheelite and calcite in a sodium oleate(NaOL)system.The suitability of LUT as a calcite depressant is confirmed through micro-flotation testing.At pH=9,with LUT concentration of 50 mg·L^(-1) and NaOL concentration of 50 mg·L^(-1),scheelite recovery reaches 80.3%.Calcite,on the other hand,exhibits a recovery rate of 17.6%,indicating a significant difference in floatability between the two minerals.Subsequently,the surface modifica-tions of scheelite and calcite following LUT treatment are characterized using adsorption capacity testing,Zeta potential analysis,Fourier transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),and atomic force microscopy(AFM).The study in-vestigates the selective depressant mechanism of LUT on calcite.Adsorption capacity testing and Zeta potential analysis demonstrate sub-stantial absorption of LUT on the surface of calcite,impeding the further adsorption of sodium oleate,while its impact on scheelite is min-imal.FT-IR and XPS analyses reveal the selective adsorption of LUT onto the surface of calcite,forming strong chemisorption bonds between the hydroxyl group and calcium ions present.AFM directly illustrates the distinct adsorption densities of LUT on the two miner-al types.Consequently,LUT can effectively serve as a depressant for calcite,enabling the successful separation of scheelite and calcite.

Impact and mechanism of bisphosphonate depressant 1-hydroxypropane-1,1-diphosphonic acid on flotation decalcification of dolomite-rich magnesite ore

Given the depletion of high-quality magnesite deposits and the rising demand for high-end magnesium materials,the separation and utilization of high-calcium magnesite ores have become essential.However,the similar surface properties and solubility of semi-soluble salt-type minerals,pose significant challenges for the utilization of dolomite-rich magnesite resources.In this study,1-hydroxypropane-1,1-di phosphonic acid(HPDP)was identified for the first time as a high-performance depressant for dolomite.Various tests,including contact angle measurements,ζ potential analysis,X-ray photoelectron spectroscopy,and atomic force microscopy,were conducted to elucidate the interfacial interaction mechanisms of HPDP on the surfaces of the two minerals at different scales.Additionally,molecular modeling calculations were used to detail the spatial matching relationship between HPDP and the crystal faces of the two minerals.It was emphasized that HPDP specifically adsorbed onto the dolomite surface by forming calcium phosphonate,ensuring that the dolomite surface remained hydrophilic and sank.Moreover,it was found that the adsorption strength of HPDP on the mineral surfaces depended on the activity of the metal sites and their spatial distribution.These findings provide a theoretical foundation for the molecular design of flotation reagents for high-calcium magnesite ores.

Antidepressant effects of Peiyuan Jieyu formula in a mouse model of chronic stress in conjunction with lipopolysaccharide-induced depression

Objective:To explore the mechanism of the Peiyuan Jieyu formula in treating depression by assessing its impact on a lipopolysaccharide-induced(LPS-induced)depression mouse model.Methods:We created a mouse model of depression by exposing mice that had previously received chronic stress to intraperitoneal LPS injections.The mice were divided into the following groups:control,model,fluoxetine,Tiansi Yin,Sini powder,and low-,medium-,and high-dose Peiyuan Jieyu formula groups.Forced swim and tail suspension tests were used to assess the efficacy of the depression(despair)model,and weight gain rates were also measured.Furthermore,serum levels of various depression and inflammation-associated molecules,including tumor necrosis factor-a(TNF-a),interferon-γ(IFN-γ),tryptophan,5-hydroxytryptamine,kynurenine(KYN),and kynurenic acid(KA)were assessed.Furthermore,the expression levels of ionic calcium-binding adaptor molecule-1(IBA-1)and indoleamine 2,3-dioxygenase(IDO)mRNA in hippocampal microglia were measured.Results:The model group displayed greater despair-associated immobility,which was shortened in response to various doses of Peiyuan Jieyu formula.Furthermore,formula administration significantly reduced serum TNF-a levels and hippocampal IDO mRNA expression.The high formula dose also reduced IFN-γand IBA-1 levels,the latter was also decreased in response to the medium formula dose.However,the low formula dose reduced serum KYN level and KYN/tryptophan(TRP)and KYN/KA ratios.Conclusion:The Peiyuan Jieyu formula holds immense potential in treating depression in a mouse model,potentially inhibiting inflammation and improving TRP-KYN metabolic disorders.

Brain region-specific roles of brain-derived neurotrophic factor in social stress-induced depressive-like behavior

Brain-derived neurotrophic factor is a key factor in stress adaptation and avoidance of a social stress behavioral response.Recent studies have shown that brain-derived neurotrophic factor expression in stressed mice is brain region–specific,particularly involving the corticolimbic system,including the ventral tegmental area,nucleus accumbens,prefrontal cortex,amygdala,and hippocampus.Determining how brain-derived neurotrophic factor participates in stress processing in different brain regions will deepen our understanding of social stress psychopathology.In this review,we discuss the expression and regulation of brain-derived neurotrophic factor in stress-sensitive brain regions closely related to the pathophysiology of depression.We focused on associated molecular pathways and neural circuits,with special attention to the brain-derived neurotrophic factor–tropomyosin receptor kinase B signaling pathway and the ventral tegmental area–nucleus accumbens dopamine circuit.We determined that stress-induced alterations in brain-derived neurotrophic factor levels are likely related to the nature,severity,and duration of stress,especially in the above-mentioned brain regions of the corticolimbic system.Therefore,BDNF might be a biological indicator regulating stress-related processes in various brain regions.

Antidepressant effects of Yuanzhi (Polygalae Radix) extract on chronic unpredictable mild stress-induced depression in rats: modulation of the NLRP3 inflammasome and NF-κB pathway

Objective To investigate the antidepressant effects of Yuanzhi(Polygalae Radix;PR)aqueous extract on chronic unpredictable mild stress(CUMS)-induced depression rat models and the underlying mechanisms.Methods A total of 40 male Sprague Dawley(SD)rats were randomly divided into control;model;low dose of PR(PR-L;0.5 g/kg);high dose of PR(PR-H;1 g/kg);and fluoxetine(10 mg/kg)groups;with 8 rats in each group.Except for the rats in control group;those in the other four groups underwent CUMS-induced depression modeling.PR and fluoxetine were administered intragastrically once daily;30 min prior to the CUMS procedure;for 14 consecu-tive days until the behavioral tests were performed.After CUMS modeling;the sucrose prefer-ence test(SPT);open field test(OFT);novelty-suppressed feeding test(NSFT);forced swim test(FST);and tail suspension test(TST)were employed to assess the pharmacological ef-fects of PR on the mitigation of depressive-like behaviors in rat models.Additionally;the en-zyme-linked immunosorbent assay(ELISA)was utilized to quantify the serum levels of tumor necrosis factor(TNF)-α;interleukin(IL)-6;and IL-1βin the rats.Western blot analysis was al-so conducted to evaluate the protein expression levels of nuclear factor kappa-B(NF-κB);in-ducible nitric oxide synthase(iNOS);cyclooxygenase-2(COX-2);nucleotide-binding oligomerization domain(NOD)-like receptor family pyrin domain containing 3(NLRP3);apoptosis-associated speck-like protein containing caspase recruitment domain(ASC);and caspase-1 in the hippocampal tissues of the rats.Immunofluorescence staining was per-formed to observe the morphological changes in ionized calcium-binding adapter molecule 1 positive(Iba-1+)cells in the dentate gyrus(DG)of rats with CUMS-induced depression.Results(i)Treatment with PR-H and fluoxetine resulted in significant enhancements in both the total distance and time the rats moved during tests(P<0.01 and P<0.05;respectively).Post-administration of PR-H and fluoxetine also led to statistically significant increase in su-crose preference among rats(P<0.05).Besides;PR-L;PR-H;and fluoxetine treatment markedly decreased the latency of ingestion(P<0.05;P<0.05;and P<0.01;respectively).As observed from the FST;PR-L;PR-H;and fluoxetine presented antidepressant effects on rats with CUMS-induced depression;leading to the reduction in time of their immobility(P<0.05;P<0.01;and P<0.01;respectively).The results of TST indicated reduced immobility time in rats receiving PR-H and fluoxetine treatment as well(P<0.01).(ii)Rats in model group showed an increase in the levels of Iba-1+microglia in their left and right brains in compari-son with control group(P<0.01).However;such increase was negated post PR treatment(P<0.01).Treatment with PR-L;PR-H;and fluoxetine considerably reduced the levels of inflam-matory factors(TNF-α;IL-1β;and IL-6;P<0.01).In addition;treatment of PR-L and PR-H ef-fectively counteracted the elevated levels of NLRP3;ASC;and caspase-1;and markedly down-regulated the expression levels of phosphorylated p65(p-p65);COX-2;and iNOS in rats’hip-pocampus(P<0.01).Conclusion Collectively;these findings indicate that PR exerts an antidepressant effect on rats with CUMS-induced depression partially through the modulation of the NLRP3 and NF-κB signaling pathways.

Association between 5-HTR1A gene C-1019G polymorphism and antidepressant response in patients with major depressive disorder:A meta-analysis

BACKGROUND Major depressive disorder(MDD)is a substantial global health concern,and its treatment is complicated by the variability in individual response to antide-pressants.AIM To consolidate research and clarify the impact of genetic variation on MDD treatment outcomes.METHODS Adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines,a systematic search across PubMed,EMBASE,Web of Science,and the Cochrane Library was conducted without date restrictions,utilizing key terms related to MDD,serotonin 1A receptor polymorphism(5-HTR1A),C-1019G polymorphism,and antidepressant response.Studies meeting inclusion criteria were thoroughly screened,and quality assessed using the Newcastle-Ottawa Scale.Statistical analyses,includingχ2 and I²values,were used to evaluate heterogeneity and fixed-effect or random-effect models were applied accordingly.RESULTS The initial search yielded 1216 articles,with 11 studies meeting criteria for inclusion.Analysis of various genetic models showed no significant association between the 5-HTR1A C-1019G polymorphism and antidepressant efficacy.The heterogeneity was low to moderate,and no publication bias was detected through funnel plot symmetry and Egger's and Begg's tests.CONCLUSION This meta-analysis does not support a significant association between the 5-HTR1A C-1019G polymorphism and the efficacy of antidepressant treatment in MDD.The findings call for further research with larger cohorts to substantiate these results and enhance the understanding of antidepressant pharmacogenetics.

Analysis of the Antidepressant Effects and Mechanisms of Icariin II Based on The GABAergic Nervous System

This article summarized the research progress on the antidepressant mechanism of icariin II,mainly elaborating on its mechanism from five aspects:GABAergic nervous system,inflammatory response,oxidative stress,neurotrophic factors,and neurotransmitters in the brain.Its clinical application value was further explored to provide a theoretical basis for the development and utilization of icariin II in treating depression.

Peripheral mitochondrial DNA as a neuroinflammatory biomarker for major depressive disorder

In the pathogenesis of major depressive disorder, chronic stress-related neuroinflammation hinders favorable prognosis and antidepressant response. Mitochondrial DNA may be an inflammatory trigger, after its release from stress-induced dysfunctional central nervous system mitochondria into peripheral circulation. This evidence supports the potential use of peripheral mitochondrial DNA as a neuroinflammatory biomarker for the diagnosis and treatment of major depressive disorder. Herein, we critically review the neuroinflammation theory in major depressive disorder, providing compelling evidence that mitochondrial DNA release acts as a critical biological substrate, and that it constitutes the neuroinflammatory disease pathway. After its release, mitochondrial DNA can be carried in the exosomes and transported to extracellular spaces in the central nervous system and peripheral circulation. Detectable exosomes render encaged mitochondrial DNA relatively stable. This mitochondrial DNA in peripheral circulation can thus be directly detected in clinical practice. These characteristics illustrate the potential for mitochondrial DNA to serve as an innovative clinical biomarker and molecular treatment target for major depressive disorder. This review also highlights the future potential value of clinical applications combining mitochondrial DNA with a panel of other biomarkers, to improve diagnostic precision in major depressive disorder.

Leaching behaviors of iron and aluminum elements of ion-absorbed-rare-earth ore with a new impurity depressant

Ion-absorbed rare-earth ore is an important mineral resource which is widely extracted by in-situ leaching process. And such process generates a significant amount of impurities such as aluminum and iron ions in leaching solution simultaneously. The surface characteristics and interactions by infrared spectroscopy and X-ray diffraction were studied to optimize the leaching conditions. It is found that the environment-friendly depressant LG-01 can react with the impurity ions through the formation of a new complex on the surface of leaching residues. Thus, it reduces significantly the concentration of impurity ions in leaching solution and improves the leaching rate of rare-earth ore. Moreover, a leaching rate of 95.6% and an impurity removal rate of 92% have been achieved under the optimized conditions.

Flotation of low-grade bauxite using organosilicon cationic collector and starch depressant

The flotation of diaspore and three kinds of silicate minerals, including kaolinite, illite and pyrophyllite, using an organosilicon cationic surfactant (TAS101) as collector and starch as depressant was investigated. The results show that both diaspore and aluminosilicate minerals float readily with organosilicon cationic collector TAS101 at pH values of 4 to 10. Starch has a strong depression effect for diaspore in the alkaline pH region but has little influence on the flotation of aluminosilicate minerals. It is possible to separate diaspore from aluminosilicate minerals using the organosilicon cationic collector and starch depressant. Further studies of bauxite ore flotation were also conducted, and the reverse flotation separation process was adopted. The concentrates with the mass ratio of Al2O3 to SiO2 of 9.58 and Al2O3 recovery of 83.34% are obtained from natural bauxite ore with the mass ratio of Al2O3 to SiO2 of 6.1 at pH value of 11 using the organosilicon cationic collector and starch depressant.

Beneficial effects of antidepressant mirtazapine in functional dyspepsia patients with weight loss

AIM: To explore the effects and mechanism of action of antidepressant mirtazapine in functional dyspepsia(FD) patients with weight loss.METHODS: Sixty depressive FD patients with weight loss were randomly divided into a mirtazapine group(MG), a paroxetine group(PG) or a conventional therapy group(CG) for an 8-wk clinical trial. Adverse effects and treatment response were recorded. The Nepean Dyspepsia Index-symptom(NDSI) checklist and the 17-item Hamilton Rating Scale of Depression(HAMD-17) were used to evaluate dyspepsia and depressive symptoms, respectively. The body composition analyzer was used to measure body weight and fat. Serum hormone levels were measured by ELISA.RESULTS:(1) After 2 wk of treatment, NDSI scores were significantly lower for the MG than for the PG and CG;(2) After 4 or 8 wk of treatment, HAMD-17 scores were significantly lower for the MG and PG than for the CG;(3) After 8 wk of treatment, patients in the MG experienced a weight gain of 3.58 ± 1.57 kg, which was significantly higher than that observed for patients in the PG and CG. Body fat increased by 2.77 ± 0.14kg, the body fat ratio rose by 4%, and the visceral fat area increased by 7.56 ± 2.25 cm2; and(4) For the MG, serum hormone levels of ghrelin, neuropeptide Y(NPY), motilin(MTL) and gastrin(GAS) were significantly upregulated; in contrast, those of leptin, 5-hydroxytryptamine(5-HT) and cholecystokinin(CCK) were significantly downregulated. CONCLUSION: Mirtazapine not only alleviates symptoms associated with dyspepsia and depression linked to FD in patients with weight loss but also significantly increases body weight(mainly the visceral fat in body fat). The likely mechanism of mirtazapine action is regulation of brain-gut or gastrointestinal hormone levels.

Neuroplasticity and major depression, the role of modern antidepressant drugs

The pathophysiology of depression has been traditionally attributed to a chemical imbalance and critical interactions between genetic and environmental risk factors, and antidepressant drugs suggested to act predominantly amplifying monoaminergic neurotransmission. This conceptualization may be currently considered reductive. The current literature about the pathophysiological mechanisms underlying depression, stress-related disorders and antidepressant treatment was examined. In order to provide a critical overview about neuroplasticity, depression and antidepressant drugs, a detailed Pubmed/Medline, Scopus, Psyc Lit, and Psyc Info search to identify all papers and book chapters during the period between 1980 and 2011 was performed. Pathological stress and depression determine relevant brain changes such as loss of dendritic spines and synapses, dendritic atrophy as well as reduction of glial cells(both in number and size) in specific areas such as the hippocampus and prefrontal cortex. An increased dendritic arborisation and synaptogenesis may instead be observed in the amygdala as a consequence of depression and stress-related disorders. While hippocampal and prefrontal functioning was impaired, amygdala functioning was abnormally amplified. Most of molecular abnormalities and biological changes of aberrant neuroplasticity may be explained by the action of glutamate. Antidepressant treatment is associated with neurogenesis, gliogenesis, dendritic arborisation, new synapse formation and cell survival both in the hippocampus and prefrontal cortex. Antidepressants(ADs) induce neuroplasticity mechanisms reversing the pathological effects of depression and stress-related disorders. The neuroplasticity hypothesis may explain the therapeutic and prophylactic action of ADs representing a new innovative approach to the pathophysiology of depression and stress-related disorders.

Utilization of polysaccharides as depressants for the flotation separation of copper/lead concentrate

The interaction mechanism between dextrin and minerals has been investigated through micro-flotation, adsorption density measurements, Fourier transform infrared ray (FTIR) spectroscopic studies and dissolution tests. Dextrin shows a good depressing action towards galena but not chalcopyrite. FTIR spectroscopic studies indicate that dextrin chemically adsorbed on galena surface in alkaline pH range. Dissolution tests confirm leaching action of metal ions from chalcopyrite and galena surfaces, and dextrin-lead ion interaction. Adsorption measurements present that the higher adsorption density of O-isopropyl-N-ethyl thionocarbamate (IPETC) onto chalcopyrite than that onto galena, and IPETC adsorbed on galena decrease with increasing dextrin concentrations in the presence of dextrin, attesting the flotation results.

Rheological Properties of Waxy Crude at a Low Temperature in the Presence of Pour Point Depressants

Pour point depressants （PPD） are used to improve the theology of waxy crude. The affect of various factors on the theological properties, and the thermal characteristics of waxy crude treated by PPD have been investigated. The conclusions are as follows： PPD can reduce the pour point and abnormal point of waxy crude, broaden the temperature range of Newtonian fluid of waxy crude, and lower greatly the viscosity of non-Newtonian fluid of waxy crude. The influence of reheating and high-rate shear on the effect of PPD mainly depends on their temperature. When the reheating temperature is more than the abnormal point of crude by 10℃, the reheating process has little effect on the modification effect of PPD. However, when the reheating temperature is below the abnormal point of crude, the reheating process will reduce the modification effect of PPD. When temperature is above the abnormal point of crude, the high-rate shear has little effect on the modification effect of PPD. At a temperature range where a lot of wax is precipitating, high-rate shear will greatly reduce the modification effect of PPD.

Synthesis of new EVA graft copolymer and its pour point depressant performance evaluation for Daqing crude oil

EVA was widely used as the pour point depressant for waxy oil.In order to improve its effect,some graft copolymerization methods should be used to modify EVA's property.EVA has long side chains and nitrogen polar groups to enforce its adaptability and effect of waxy oil.The pure amine,maleicanhydride and their reaction product were tested using infrared spectra and the NMR spectral.The results show that when the modified EVA is added into oil,the wax deposits not only on the main chain but also on the side chains.And the polar groups have the function to avoid and resist the wax crystals connection each other to form the net.Using the reaction product of maleicanhydride and high carbonic amine(C12,C16,C18 amine) as the graft component,the toluene as the solvent and BPO as the initiator,the series of new EVA graft copolymer with special side chains are prepared under controlled condition.A series of cylmaleimide exist indeed in modified EVA and the highest grafted percentage is 18.8%.EVA-16,the new graft copolymer,is better than EVA about 3 ℃ more in depressant the pour-point of Daqing waxy crude oil.

Antidepressant foods:An evidence-based nutrient profiling system for depression

AIM To investigate which foods are the most nutrient dense sources of nutrients demonstrated by the scientific literature to play a role in the prevention and promotion of recovery from depressive disorders. METHODS A systematic literature review was conducted to derive a list of Antidepressant Nutrients from the 34 nutrients known to be essential for humans using level of evidence criteria. Nutritional data was extracted for a subset of foods with a high content of at least 1 Antidepressant Nutrient using a USDA database. These foods were analyzed for Antidepressant Nutrient density resulting in an Antidepressant Food Score(AFS). Plant and animal foods were analyzed separately. RESULTS Twelve Antidepressant Nutrients relate to the prevention and treatment of depressive disorders: Folate, iron, longchain omega-3 fatty acids(EPA and DHA), magnesium, potassium, selenium, thiamine, vitamin A, vitamin B6, vitamin B12, vitamin C, and zinc. The highest scoring foods were bivalves such as oysters and mussels, various seafoods, and organ meats for animal foods. The highest scoring plant foods were leafy greens, lettuces, peppers, and cruciferous vegetables. CONCLUSION The AFS is based on a nutrient profiling system devised to identify foods with the highest nutrient density of nutrients with clinical evidence to support theirrole in depressive disorders. This list of foods and food categories with the highest density of the 12 Antidepressant Nutrients, the Antidepressant Foods, should be considered by researchers in the design of future intervention studies and clinicians as dietary options to support prevention and recovery from depression disorders.

Molecular structures and activity of organic depressants for marmatite,jamesonite and pyrite flotation

Ten kinds of organic depressants were used to investigate the depressing performance on marmatite and pyrite.Flotation results show that the organic compounds only with single group of hydroxyl(-OH),carboxyl(-COOH) or amino(-NH2) in molecule are ineffective in depressing marmatite,jamesonite and pyrite.The combinations of these functional groups still cannot enhance the depressing ability of organic depressant.The thioglycollic acid containing reductive functional group(-SH) has a good depressing performance for marmatite and pyrite.The presence of benzene ring in molecule can enhance the depressing performance.The functional group electronegativity,hydrophilic-hydrophobic indexes and frontier orbital of organic depressants were calculated,and the criterion for the depressing effect of organic depressants to sulphide minerals was proposed.

Effect of organic depressant lignosulfonate calcium on separation of chalcopyrite from pyrite

In order to selectively separate chalcopyrite from pyrite,the effect of organic depressant lignosulfonate calcium(LSC) on the flotation separation of chalcopyrite from pyrite was investigated by flotation tests. The depression mechanism was studied by Fourier-transform-infrared(FTIR) analysis. The flotation tests of single mineral show that LSC can depress the flotation of pyrite in a certain pH range,but it has little effect on chalcopyrite flotation. Flotation separation of a mixture of chalcopyrite and pyrite can be completed to obtain a copper concentrate grade up to 24.73% with a recovery of 80.36%. IR analysis shows that LSC and butyl xanthate compete in absorption on pyrite surface,and there exists an LSC characteristic peak on pyrite surface. There is little adsorption of LSC on chalcopyrite.