煤炭高梯度磁选-浮选脱硫降灰试验

通过分析煤样性质,说明原煤中无机硫主要以硫化铁硫为主,有机硫较高,仅依靠物理方法很难达到理想脱除效果。通过煤粉高梯度磁选试验研究了磁介质、磁通密度、脉冲对煤炭磁选效果的影响。结果表明:聚磁介质选用不加铜套细网介质,当磁通密度为1.295 T,脉冲为25次/min时,煤粉湿法高梯度磁选脱硫效果最好,此时硫分为1.59%,精煤产率为85.44%,脱硫率为31.87%,脱灰率为38.17%,黄铁矿硫脱除率为45.02%。通过正交试验确定了最佳高梯度磁选条件为:煤粉粒度0.075 mm,磁通密度1.295 T,脉冲25次/min,可得到硫分1.35%,灰分10.37%的磁选精煤产品。最后对磁选精煤进行再浮选试验,得到最佳浮选条件为:石灰500 g/t,捕收剂1360 g/t,起泡剂90 g/t,可获得产率76.29%,硫分1.28%,灰分8.14%的精煤,产品脱硫率为57.73%,脱灰率为58.52%,黄铁矿硫脱除率为84.56%。采用磁选-浮选综合流程,煤粉基本达到理想的脱硫降灰效果,可作为煤种脱硫降灰技术方案的参考。     

中灰分煤解离浮选试验研究

为了探索中灰分煤解离浮选脱硫降灰的可行性，利用磨矿方法对1.4～1.5 kg/L密度级煤样进行解离试验，并对各解离程度的煤样进行浮选分步释放试验。试验结果表明：磨矿可以使煤样充分解离，低灰物料累计产率可达78%,随着解离程度的提高，解离后1.4～1.5 kg/L密度级物料的灰分显著降低；浮选方法很难高效地将小于200网目低灰物料回收，且无机硫易污染低灰煤炭；煤样磨矿至小于120网目最有利于浮选，灰分为12%时，理论浮选精煤产率约为32%,理论浮选精煤硫分约为1.10%。中灰煤磨矿解离浮选有助于提高精煤产率。     

细粒煤浮选磁选联合脱灰脱铁试验研究

为获得满足工业硅生产所需的低灰低铁烟煤,以云南省某煤矿细粒煤泥为试验对象进行磁选、浮选单独脱铁脱灰试验研究,获得最佳磁选、浮选条件,并在此基础上进行浮选磁选联合脱灰脱铁试验。结果表明：磁场强度为1.701 T、煤泥粒度为-0.25 mm时,煤泥磁选、浮选效果较好,可获得相对较高的脱铁率和脱灰率。通过对比先浮选后磁选及先磁选后浮选2种试验流程及分选效果,最终选用先浮选后磁选试验流程,该流程中浮选精煤只需简单调浆即可直接用于磁选,省去了一次过滤,经济效益显著。控制精煤产率在62.08%时,能获得灰分5.94%、铁含量0.28%的合格精煤,达到了工业硅冶炼用烟煤灰分〈6%、铁含量〈0.3%的要求。     

超声预处理对浮选柱脱硫降灰影响的探索研究

由于原煤泥硫分高,硫赋存形式复杂,为改善高硫煤泥浮选脱硫效果,提高精煤产率,采用煤浆超声波预处理联合浮选柱脱硫的工艺方案;对比了不同超声波预处理试验方案,找出了较佳的试验条件,并进行了正交试验和分步释放试验,得到了灰分17.98%、硫分1.41%、产率19.26%的精煤;根据原煤特性和试验结果提出了下一步改进脱硫效果的方向。     

高硫煤深度浮选联合化学氧化脱灰脱硫提质研究

随着我国优质煤资源逐渐减少,高硫煤等劣质煤的开发利用是保障煤炭能源安全的重要途径,而高硫煤脱灰脱硫提质是高硫煤清洁高效利用的首选方案。采用深度浮选联合氧化方法对贵州某高硫煤进行脱灰脱硫提质研究,通过接触角测试不同捕收剂的性能,研究不同捕收剂对浮选脱灰的影响规律,不同灰分抑制剂和硫分抑制剂对浮选脱灰脱硫的影响,并进行闭路浮选试验。采用化学氧化对浮选精煤进一步脱硫处理,研究了不同氧化剂对浮选精煤化学脱硫的影响规律,并通过红外光谱和扫描电镜证明脱灰脱硫机理。结果表明,与柴油相比,复合捕收剂M7015对浮选脱灰更有优势,原煤接触角为62.5°,M7015处理后煤炭接触角提高了15.0°,柴油处理后接触角提高了5.0°,M7015最佳用量为800 g/t。Ca O作为脱硫抑制剂效果较好,用量为4 000 g/t,灰分抑制剂S-4的最佳用量为1 000 g/t。经过"一粗—二扫—二精"闭路浮选试验流程,得到灰分5.62%、硫含量1.34%的浮选精煤。双氧水和冰醋酸混合液的氧化脱硫效果最佳,浮选精煤经氧化处理后得到灰分5.60%、硫含量0.88%的低灰低硫精煤。SEM分析表明附着在煤炭表面的颗粒减少,表面光滑,裂缝之间的矿物颗粒明显减少,深度浮选脱灰脱硫效果明显。红外光谱表明深度浮选联合化学氧化不改变煤炭的基本结构,能脱除大部分灰分,浮选脱除大部分黄铁矿等无机硫,化学氧化脱除硫醚和亚砜等部分有机硫。说明深度浮选联合化学氧化的新工艺实现了高硫煤脱灰脱硫提质,得到高品质低灰低硫精煤产品。     

高灰氧化煤的浮选试验研究

针对高灰氧化煤存在的细粒级含量大、灰分高、难浮选等问题,研究了浮选机、浮选柱对高灰氧化煤浮选效果的影响,考察了脂肪醇(乙醇和丁醇)对氧化煤的去氧化作用。浮选机试验表明:经促进剂处理后,煤样浮选效果明显改善,与空白试验相比,丁醇处理后煤样的可燃体回收率提高了12.99%,精煤灰分降低了16.63%;丁醇改善氧化煤浮选效果的能力要强于乙醇,可燃体回收率提高了1.30%～11.43%,精煤灰分降低了0.21%～1.46%。浮选柱试验表明:丁醇对高灰氧化煤的浮选柱分选效果较乙醇好,在循环泵压力为0.16 MPa时,煤泥浮选效果最好,可燃体回收率为38.55%,精煤灰分为19.49%,比相同药剂条件下浮选机试验的可燃体回收率提高了6.26%,精煤灰分降低了3.32%。因此,经脂肪醇预处理后,煤泥浮选效果明显提高,且浮选柱的分选效果要好于浮选机。     

旋流微泡浮选柱在涡北选煤厂的应用

分析了涡北选煤厂煤泥粒度组成,发现煤样矸石存在泥化现象,高灰细泥含量较高,对浮选不利。进行了浮选机的单因素浮选试验、两因素三水平正交试验以及最优药剂条件下的分步释放试验,同时进行了浮选柱的煤泥浮选试验。结果表明,当煤泥矿浆质量浓度为45 g/L,复合药剂为1.10 kg/t时,精煤灰分为10.97%,精煤产率为72.62%,浮选完善指标最高为53.43%,浮选机煤泥浮选效果最好;浮选柱可以分选出各种质量的精煤,精煤灰分可调性大,可以适应市场变化。最后进行了浮选机和浮选柱的综合对比试验,在精煤灰分相近的情况下,浮选柱不同程度地提高了精煤回收率和浮选完善指标,具有明显优势。     

细粒难浮煤泥浮选试验研究

分析了内蒙古能源中心选煤厂煤泥性质,说明试验煤泥是以高灰细泥为主的极难浮煤;高灰细泥在浮选过程中容易因夹带、黏附作用而进入精煤,影响精煤质量。通过探索试验发现,煤浆质量浓度为40∥L,捕收剂、起泡剂用量均为1．0kg／t时,煤泥浮选效果最好,此时精煤产率为53．53％,灰分为13．92％,但仍未达到厂家要求。为将精煤灰分降至11％以下,对煤泥进行二次浮选试验。当煤浆质量浓度为50g／L,捕收剂、起泡剂用量均为1．5kg／t,搅拌时间为1min时,二次浮选效果最好,此时精煤产率为52．78％,精煤灰分为10．14％,中煤产率为6．57％,中煤灰分为57．30％,尾煤产率为40．65％,尾煤灰分为76．81％,中煤可直接出售。二次浮选工艺可有效降低精煤灰分,提高精煤产率,解决了煤泥难浮问题,满足了生产需求。     

基于正交试验的浮选药剂制度优化

龙口选煤厂近期入选原煤煤质变化较大,浮选入料高灰细泥含量增高,导致浮选效果变差,浮选精煤灰分升高,重选为浮选"背灰"。为降低高细泥含量煤泥的精煤灰分,通过正交试验用浮选完善指标、精煤产率来评价浮选效果,找出最佳药剂用量为:捕收剂0.26 kg/t干煤泥,起泡剂为0.15 kg/t干煤泥,实现了精煤灰分小于9.50%,浮选数量效率达到90.85%的工艺指标。     

浮选入料预先脱泥及浮选试验研究

某炼焦煤选煤厂煤泥存在产量大、灰分高、其中高岭石和地开石含量多等问题,为有效解决上述问题,首先通过筛分试验、浮沉试验和矿物组成分析试验,计算各粒级和密度级煤样的产率和灰分等质量指标,分析煤泥的可选性和矿物组成。采用?75 mm水力旋流器预先脱泥进行压力试验,结果表明：最佳入料压力0.20 MPa,矿浆质量浓度15%,此时底流产率26.27%、灰分39.21%;溢流产率73.73%、灰分52.33%,底溢流灰分差为13.12%,说明水力旋流器具备脱泥降灰的能力。煤泥经预先脱泥处理后,将?75 mm旋流器底流产物进行浮选,设计浮选试验工艺流程为一次粗选和一次扫选。浮选试验结果表明：旋流器底流浮选的精煤产率为41.38%、可燃体回收率为61.30%,与原煤泥直接进行浮选相比精煤产率和可燃体回收率分别提高了11.14%和7.64%。说明经过水力旋流器预先脱泥可有效提高煤泥可浮性。     

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.     

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。     

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.