基于强磁预选的某氰化尾渣磁化焙烧-磁选工艺

以TFe品位为30.71%的河南某焙烧氰化尾渣为原料,采用湿式强磁预选?磁化焙烧?磁选联合工艺制备铁精粉. 结果表明,当强磁预选的磁场强度为1511.54 kA/m时,得到TFe品位44.96%、回收率78.27%的粗精矿;以该粗精矿为磁化焙烧原料,配10wt%焦粉,于750℃下磁化焙烧45 min,焙烧样经二段磨矿、二段弱磁选,当二段磨矿细度小于0.028 mm占63.9%时,可得TFe品位61.71%、回收率68.66%的铁精粉;产率为16.79%的弱磁选尾矿不含氰化物,转化为一般工业固体废物. 焙烧温度低于700℃时,部分赤铁矿未还原;焙烧温度超过800℃时,生成的磁铁矿转化成镁铁矿、铁橄榄石和方铁矿,磁铁矿含量降低,导致铁损失;焙烧温度为750℃时,磁铁矿含量最高.     

菱铁矿磁化焙烧与磁选分离制备铁精矿

对国内某地菱铁矿进行无还原剂全粒级磁化焙烧-磁选研究. 结果表明,菱铁矿在无还原剂条件下于800℃焙烧15 min,所得焙烧矿在磨矿粒度小于0.074 mm占90%、磁场强度0.10 T条件下磁选,得到铁品位63.15%、铁回收率92.52%的铁精矿. 磁选精矿中的锰、镁和部分钙与铁元素以类质同像共存.     

低品位硼铁矿中铁资源的富集回收

提出了一种回收低品位硼铁矿(TFe 30.23%)中铁资源的方法.采用还原焙烧、磁选工艺流程,按原子比C/O=1进行配碳,使用马弗炉进行焙烧,研究了不同焙烧温度下铁精粉品位和铁回收率的变化趋势及相互关系.研究结果表明,在1150℃以下焙烧时铁精粉品位和铁的回收率呈反向变化,当焙烧温度为1200℃以上时,铁精粉品位和铁的回收率呈同向变化,此时铁品位可达80%以上,回收率同时达到90%以上     

高磷铁矿含碳团块直接还原-磁选提铁

采用直接还原?磁选工艺从湖南某地高磷铁矿含碳团块中提铁,研究了还原温度、还原时间、团块碱度、还原剂焦粉用量、添加剂Na2SO4用量和废塑料替代焦粉量等因素对磁选精矿指标的影响. 结果表明,在还原温度1150℃、还原时间40 min、团块碱度0.8、碳氧摩尔比0.9的条件下,添加4% Na2SO4同时添加废塑料替代25%焦粉,可得到金属化率为88.77%的焙烧矿,磁选后可得到铁品位91.99%、金属化率92.26%及P含量0.20%的金属铁粉,铁回收率达86.74%.     

川西地区某锂辉石矿选矿试验探讨

对川西某锂辉石矿的矿石特征进行了研究,在此基础上进行了重选试验、浮选试验以及含铁锂辉石精矿再选降铁试验,提出了采用重选加磁选回收钽铌矿物及锡石,浮选回收锂辉石的工艺流程。采用螺旋溜槽粗选、摇床精选得到钽铌和锡石混合精矿,通过磁选可有效分离钽铌矿物和锡石,最终获得精矿品位Ta_2O_5为19.66%、回收率43.78%,SnO_2品位为67.56%、回收率45.53%的指标;采用碳酸钠和氢氧化钠调浆,氧化石蜡皂、环烷酸皂为捕收剂,经一粗二扫的浮选流程可得到精矿品位Li_2O为6.04%,回收率85.88%的较好指标;对含铁锂辉石精矿经过弱磁、强磁选别后,再经酸洗处理,可提高锂辉石精矿品位,降低其铁含量。     

硫铁矿炼磺渣选铁还原焙烧磁选还原剂试验研究

根据炼磺渣的性质,采用预选抛尾的方法预选了试样,在此基础上,分别进行了预选粗精矿还原焙烧的还原剂种类、还原剂用量、还原剂粒度、磁选磁场强度试验。试验表明:预选粗精矿焙烧时间在20 min,温度在850℃时,还原剂种类以焦炭、还原剂用量以5%、还原剂粒度以-1mm、磁场强度以0.29 T为宜,得到的铁品位为51.71%,铁回收率为77.20%。     

磁选技术在车河选矿厂的应用研究

针对车河选矿厂原矿中铁丝、铁块等杂物多、枱浮摇床及+74摇床精矿锡品位较低且铁含量高、细粒级锡石全浮选流程回收率低且药剂消耗量大、锌硫分离尾矿未得到综合利用的问题,开展了原矿除铁试验研究、枱浮摇床给矿及精矿磁选试验研究、+74摇床精矿磁选试验研究、30米脱硫浮选给矿及一次浮锡精矿磁选试验研究、锌硫分离尾矿磁选试验研究等一系列研究,并在生产中得到应用,最终磁出原矿中铁质杂物50 kg/班,减少了流程堵塞及设备磨损;枱浮摇床精矿铁含量由17.1%降至13.2%;+74摇床精矿锡品位由42.5%提高至47.1%、铁含量由23.9%降至11.6%;细粒级锡石回收率提高1.01个三分点;锌硫分离尾矿得到综合回收利用。本次研究效果显著。     

硫酸渣磁选获取铁精矿粉实验研究

采用氧化脱硫，磁化焙烧及湿式磁选工艺路线，处理硫酸渣后所得精矿粉其总铁品位提高，硫，磷含量降低，基本满足工业炼铁原料要求。     

硫酸钠作用下褐铁型红土矿选择性还原富集镍铁

以Na2SO4为添加剂,采用煤基还原-磁选工艺,对含Ni 1.17%和Fe 35.71%的褐铁型红土矿选择性还原富集镍铁的行为进行了研究.结果表明,原矿中27.40%的镍以氧化物形式存在,69.35%的镍以硅酸盐形式存在;在还原温度1100℃、还原时间60 min、硫酸钠用量20%(?)、无烟煤用量8%(?)的最佳还原条件下,在200 m T的磁场强度下湿式磁选,可富集得到镍品位13.26%、镍回收率88.4%、铁品位67.34%、铁回收率14.71%的镍铁精矿,镍富集比达11.33.红土镍矿还原过程中加入Na2SO4破坏了原矿中硅酸盐的结构,释放出其中的镍与铁,进一步生成Fe S,抑制铁深度还原并降低了体系熔点,有利于金属离子传质,促进镍铁颗粒长大.     

鲕状赤铁矿磁化焙烧-磁选过程研究

以鄂西某鲕状赤铁矿为研究对象,考察了焙烧时间对其磁化焙烧与磁选过程、相态转化及焙烧变化规律的影响. 结果表明,含铁鲕粒多数由赤铁矿内核与致密同心外壳及其中间夹带的脉石矿物构成;含铁(TFe) 49.02%的鲕状赤铁矿在800℃下磁化焙烧60 min后再用磁选管分选,获得含铁56.34%、铁回收率为88.05%的较好结果,焙烧时间对磁化焙烧影响显著. 磁化焙烧过程仅改变铁相,而鲕粒结构未变;磁化还原由表及里受扩散作用控制,还原程度随焙烧时间延长逐步增加. 800℃下焙烧时间小于30 min时,极少过还原生成FeO,之后则有少量FeO生成,较少形成Fe2SiO4;含磷与含硅矿物均有相变,但转变时间不同.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。