电解铝大修渣处理研究进展

铝电解大修渣是铝电解槽维修及废弃产生的固体废物,其中含有超标的毒性物质氟化物和氰化物,严重污染环境。本文主要介绍了大修渣的成分,危险属性和目前大修渣的处置及资源综合利用技术。同时也为电解铝企业在处理大修渣方面提供新的思路和技术指导,希望能帮助减轻企业负担,增加创收。     

电解铝工业危废处置技术现状与发展趋势

详细介绍了国内外电解铝大修渣处置技术的发展现状,分析和研究我国电解铝大修渣的处置技术面临的瓶颈和问题,围绕政策、传统技术以及国外技术在国内推广情况进行剖析,指出了我国电解铝危废大修渣废槽衬和废阴极的处置技术发展方向。     

浅析电解铝厂大修废渣的处理方式

阐述了电解铝厂生产过程中产生的电解槽大修废渣的处理方式,包括对大修渣的产生原因、环境影响、运输方式、渣场场址选择、堆存方式及废渣的回收再利用等作了详细的分析.     

浅析电解铝厂大修废渣的处理方式

阐述了电解铝厂生产过程中产生的电解槽大修废渣的处理方式,包括对大修渣的产生原因、环境影响、运输方式、渣场场址选择、堆存方式及废渣的回收再利用等作了详细的分析。     

浅析电解铝厂大修废渣的处理方式

阐述了电解铝厂生产过程中产生的电解槽大修废渣的处理方式，包括对大修渣的产生原因、环境影响、运输方式、渣场场址选择、堆存方式及废渣的回收再利用等作了详细的分析。     

武钢2号高炉大修采用的新技术及冶炼效果

武钢2号高炉(1536m~3)于1997年3月底停炉大修,1998年11月13日点火送风。高炉设有20个风口(大修前为24个),采用双铁口,夹角36°,保留低渣口,取消高渣口。通过这次改造性大修,高炉技术装备水平得到提高,如:用串罐无料钟炉顶取代双钟双     

永登铝业开工建设电解大修渣无害化处理项目

日前,河南永登铝业有限公司"电解槽大修渣无害化处理项目"在该公司阳城分公司正式开工建设。该项目计划投资670万元,建成后每年可以处理电解槽大修废渣500 t。铝电解槽进行大修时,从槽壳内清理出来电解槽内衬主要为耐火材料、碳素材料等,这些废渣不同     

莱钢股份炼铁厂高炉渣处理设备改造实践

针对莱钢股份炼铁厂4号高炉渣处理设备存在的隐患和磨损严重使用寿命短的现状,通过对设备的大修和技术改造,延长了渣处理系统的使用寿命,提高了设备的性能,保证了设备的高效运行,为高炉的安全生产奠定了基础。     

用链带式活动滤槽法处理高炉水渣的设想

笔者在从事涟钢新3号高炉易地大修的设计中,针对以下情况:①新3号高炉场地狭小且无法利用原有水渣池;②涟钢高炉冲渣水时常不足,上下渣经常堆积;③冲渣沟内时常积有大块的干渣与小铁块,由于冲渣沟道很长且属高架式,清理困难且不安全,曾提出了一种新的高炉水渣处理方案——链带式活     

铝电解槽大修渣的环境风险管控思路浅析

结合电解铝行业大修渣环保管理的现状,分析了企业在铝电解大修渣的产生、收集、贮存、运输、利用和处置全过程中环境风险管控存在的配套基础设施弱、缺乏成熟稳定的处置技术、缺乏技术规范标准的引导、协同处置和利用难等问题,并提出在源头开展减量化、建立健全污染防治责任、全过程管理合规化、推进技术攻关和协同处置规模化信息化、积极为相关政策制修订提供技术和实践支撑等管控措施。     

Plasma containing artemether-pyrimethamine has ex vivo blood schizonticidal activity against Plasmodium falciparum

Four Eptesicus fuscus were trained in a range discrimination experiment to choose the closer of two phantom targets. Echo attenuation was roving between trials returning echoes ranging from -10 dB to -50 dB SPL (sound pressure level) relative to emission SPL. Discrimination thresholds were determined. After sufficient training, ranging performance was stable and about the same in the range between -20 dB and -50 dB with range difference thresholds around 300 microseconds. At -10 dB, performance was poor even after long training. After additional training at a constant relative echo SPL of -30 dB and a delay difference of 300 microseconds the performance measured with roving echo SPL improved at all relative echo SPL between -20 dB and -50 dB but not at -10 dB. The new experimental procedure improved the performance by additional learning, and the bats generalized over a wide range of relative echo SPL. Threshold improved to 100 microseconds when measured at a constant relative echo SPL of -30 dB, again indicating the influence of the experimental procedure. In correspondence to neurophysiological data the ranging performance deteriorates if the echo SPL is close to the emission SPL. Signal duration and emission SPL were variable during range discrimination.     

Hemodynamic effects of short-term noise exposure--comparison of steady state and intermittent noise at several sound pressure levels

The purpose of the present study was to investigate the extent of blood pressure elevation during noise exposure, to elucidate the underlying hemodynamic mechanisms and to assess baroreceptor cardiac reflex sensitivity in connection with blood pressure elevation. Twenty-two young normotensive males participated in the experiment and underwent six noise exposure conditions of 20 min each: steady state and intermittent pink noises of 80 dB (sound pressure level (SPL)), 90 dB (SPL) and 100 dB (SPL). The results indicate that elevations in mean arterial pressure, as well as diastolic and systolic blood pressure, were significant or almost significant in the intermittent 100 dB (SPL) and 90 dB (SPL) conditions. Habituation occurred particularly with the steady state noises. In at least the intermittent 100 dB (SPL) condition, an increase in peripheral vascular resistance was the underlying hemodynamic mechanism of blood pressure elevation. Decreases in cardiac output and stroke volume were also associated with the peripheral vasoconstriction. Baroreceptor reflex sensitivity was maintained near the baseline level for all of the noise exposure conditions. Therefore, reflex sensitivity may not have been suppressed even in the intermittent 100 dB (SPL) condition during which blood pressure elevations occurred.     

Intentional changes in sound pressure level and rate: their impact on measures of respiration, phonation, and articulation

The purpose of the study was to compare the effects of changing sound pressure level (SPL) and rate on respiratory, phonatory, and articulatory behavior during sentence production. Ten subjects, 5 men and 5 women, repeated the sentence, "I sell a sapapple again," under 5 SPL and 5 rate conditions. From a multi-channel recording, measures were made of lung volume (LV), SPL, fundamental frequency (F0), semitone standard deviation (STSD), and upper and lower lip displacements and peak velocities. Loud speech led to increases in LV initiation, LV termination, F0, STSD, and articulatory displacements and peak velocities for both lips. Token-to-token variability in these articulatory measures generally decreased as SPL increased, whereas rate increases were associated with increased lip movement variability. LV excursion decreased as rate increased. F0 for the men and STSD for both genders increased with rate. Lower lip displacements became smaller for faster speech. The interspeaker differences in velocity change as a function of rate contrasted with the more consistent velocity performance across speakers for changes in SPL. Because SPL and rate change are targeted in therapy for dysarthria, the present data suggest directions for future research with disordered speakers.     

Otoacoustic emissions evoked by electrical stimulation

Otoacoustic emissions evoked by electrical stimulation of the cochlea were measured in guinea pigs. Alternating current with acoustic frequencies was delivered directly to the scala tympani and the vestibuli of the basal turn by using a constant current stimulator made in our laboratory. The amplitude of the electrically evoked otoacoustic emmisson (EEOAE), which was 21.0 dB SPL in response to 2 kHz electrical stimuli of 120 microArms, was decreased gradually with anoxia of the animal and was reduced to below the noise level by extirpation of the ossiculum. The EEOAEs rose with a delay of 100 microseconds from the beginning of the stimulus, and reached maximum amplitude within three cycles. The output of EEOAE was magnified in a linear manner as the stimulus current increased from 10 to 200 microArms. The averages and standard deviations of the EEOAE output at the stimulus level of 170 microArms in six animals were 20.5 +/- 4.1 dB SPL for 1 kHz, 23.3 +/- 4.8 dB SPL for 2 kHz, 10.5 +/- 6.0 dB SPL for 3 kHz, 17.1 +/- 4.7 dB SPL for 4 kHz, 13.6 +/- 4.4 dB for 5 kHz and 18.3 +/- 4.8 dB SPL for 6 kHz. Measurement of EEOAE, in which stable responses could be obtained with simple and easy preparation, was considered a potential procedure for assessing the electromotility of the cochlear outer hair cells in vivo.     

Numerical simulation of copper recovery from converter slags by the utilisation of spent potlining (SPL) from aluminium electrolytic cells

An innovative method was devised to improve copper recovery and operational efficiency of the Cu converter slag-cleaning furnace, by utilising both carbon and fluoride values of an otherwise environmental hazardous material (i.e. spent potlining (SPL)) produced from the aluminium industry. Results based on numerical modelling show that 90% Cu recovery could be achieved by adding as little as 3–4?wt-% of SPL to the molten converter slag. The fluorides and sodium-containing compounds in the SPL reduced the slag viscosity, resulting in a much faster settling rate of matte droplets. In this process, the SPL could be detoxified by destroying the cyanides to form harmless N₂ gas, and inertising the fluorides in a much diluted form in the ferro-silicate slag, ensuring a safe disposal to the environment.     

Recovery of neonatal head turning to decreased sound pressure level.

Human newborns' responses to decreased sound pressure level (SPL) were investigated with a localized head-turning habituation procedure. Recovery to a decrement in volume contradicts a selective receptor adaptation view because a lower intensity stimulus does not engage a separate set of receptor cells. Ninety-six infants (mean age 41 hrs) were presented with the same sound for 2 infant-controlled phases. After criterion orientation (3 head turns toward the sound in 4 consecutive trials) and criterion habituation (3 consecutive trials with no head turns or head turns away) to 1 of 2 stimulus intensities (72 or 78 dB [SPL]), infants were randomly assigned to test trials at an intensity of 66, 72, or 78 dB (SPL). Planned comparisons of percentage of test trials with head turns toward the sound revealed that decreased SPL produced recovery of localized head turning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prevention of hearing loss in experimental pneumococcal meningitis by administration of dexamethasone and ketorolac

Pneumococcal meningitis remains a significant cause of morbidity, particularly sensorineural hearing loss. Recent literature has suggested that a vigorous host immune response to Streptococcus [corrected] pneumoniae is responsible for much of the neurologic sequelae, including deafness, after bacterial meningitis. This study used a rabbit model of hearing loss in experimental pneumococcal meningitis to evaluate the therapeutic effect of two anti-inflammatory agents, dexamethasone and ketorolac, coadministered with ampicillin. Both adjunctive drugs minimized or prevented sensorineural hearing loss compared with placebo. Dexamethasone, administered 10 min before ampicillin, was particularly effective in minimizing mean hearing threshold change compared with placebo for both clicks (dexamethasone: 6.7-dB sound pressure level [SPL] vs. placebo: 33. 4-dB SPL, P=.0078) and 10-kHz tone bursts (dexamethasone: 8.4-dB SPL vs. placebo: 53.4-dB SPL, P=.0003). These findings support the beneficial role of anti-inflammatory agents in reducing the incidence of hearing loss from pneumococcal meningitis, especially if therapy is instituted early in the course of infection.     

Synthesis of a novel sialic acid derivative (sialylphospholipid) as an antirotaviral agent

A novel sialylphospholipid (SPL) was synthesized from N-acetylneuraminic acid (NeuAc) and phosphatidylcholine (PC) by a chemical and enzymatic method and evaluated as an inhibitor of rotavirus. PC and 1,8-octanediol were conjugated by transesterification reaction of Streptomyces phospholipase D (PLD) under a water-chloroform biphasic system to afford phosphatidyloctanol, which was condensed with a protected 2-chloro-2-deoxyneuraminic acid derivative by using silver trifluoromethanesulfonate as an activator in chloroform and converted, after deprotection, to SPL. Rhesus monkey kidney cells (MA-104) were incubated with simian (SA-11 strain) and human (MO strain) rotaviruses in the presence of SPL, and the cells infected were detected indirectly with anti-rotavirus antibody. SPL showed dose dependent inhibition against both virus strains. The concentrations required for 50% inhibition (IC50) against SA-11 and MO were 4.35 and 16.1 microM, respectively, corresponding to 10(3)- and 10(4)-fold increases in inhibition as compared to monomeric NeuAc.     

István Csapody

This pilot study compared the susceptibility of the infant (48 hr) and adult (120 days) guinea pig to the effects of noise. Subjects were exposed to a narrow band of noise (center frequency 4 kHz) at an intensity of 115 dB sound pressure level (SPL) for 1 hr. Postexposure thresholds were obtained by a conditioned suppression technique. Results indicated that the infant animals displayed a mean hearing threshold of 25 dB SPL that significantly differed from the adult mean threshold of 7.5 dB SPL.     

Remote masking generated by high-frequency two-tone complexes

Auditory masking generated by two-tone complexes centered around 7 000 Hz was measured in 10 young adults with normal hearing sensitivity as a function of the frequency separation (deltaf) and SPL of the masker's components. Remote masking (1) was evident for test signals in the frequency region corresponding to the masker's deltaf; (2) increased with masker SPL, but at a rate less than that usually observed when lower frequency bands of noise are used as maskers, and (3) was relatively constant in magnitude for a given SPL as a function of the masker's deltaf. The masking produced in low-frequency regions by high-frequency two-tone complexes adds support to the hypothesis that remote masking is primarily a result of aural distortion.