木炭替代品—一项具有应用前景的研究

论述了为保护自然资源研究木炭替代品的必要性与可行性。就替代品的原料选择,处理方法和工艺条件进行了详细描述。     

工业硅生产中碳质还原剂的选择

介绍了工业硅生产中常用的木炭、石油焦、烟煤及蓝炭等碳质还原剂的物理化学性质，并对烟煤和蓝炭作为木炭替代品做了可行性分析，得出：在工业硅生产中，根据具体情况选择几种合适的碳质还原剂替代单一的还原剂，是一种行之有效的办法，并在生产践中取得了良好的效果。     

铁矿石在硅铁生产中的应用

为了寻求更好的硅铁生产铁质原料替代品,降低生产成本,采用铁矿石代替铁球团矿进行生产实验,从原料使用情况到生产实践作了计算、分析和对比,证明了其可行性和实用性。     

炼铁过程使用木炭和生物质以及废塑料减少CO2的排放

根据实验室研究,提出了两种可应用于钢铁行业降低CO2排放的方法:利用可再生的生物质或木炭以及利用可回收的含氢废旧塑料。该方法可通过以下两个途径实现:①风口喷吹;②混入入炉炉料,例如:通过混入炼焦煤而进入焦炭,在生产用于高炉或直接还原的球团原料中添加含碳原料和塑料。为考察现代高炉风口喷吹木炭的益处,重点研究了木炭在风口回旋区的气化行为和在风口回旋区外的二次反应。采用实验室装置及其相应的检测设备,研究了几种木头在不同炭化条件下所得到的木炭的转化效率。研究结果表明,对于风口喷吹,所测试木炭的燃烧行为都不逊于矿物质煤;在模拟的高炉炉身条件下,木炭的熔损反应速率高于试验所用的矿物质煤。使用塔姆曼炉试验装置及检测仪研究了可用于直接还原和高炉的冷固结含碳、废塑料和木炭球团的还原和体积变化行为。使用该种球团可抑制和减小还原膨胀,甚至出现体积收缩。球团的自还原行为受还原气的量、气氛和操作条件的影响。采用电阻炉进一步研究了固结废塑料(聚乙烯和垃圾衍生燃料)的氧化铁的还原行为。     

巴西钢铁工业的能量效率以及CO_2减排

不同钢铁企业为竞争获得诸如世界杯(2014)和奥运会(2016)等大量钢铁产品的供应,相继宣布了一些大的投资项目,巴西的钢铁行业可能会在2010—2020的十年间显著增长。巴西虽以巨大的优质铁矿储藏闻名,但却呈现出一个有趣的特征,即存在一个基于木炭的由超过160座采用再生能源取代化石原料的小高炉组成的独立生铁部门。概述了巴西钢铁工业节能和温室气体排放的相关足迹,包括巴西钢铁工业的发展和现状。概述了基于木炭的生铁工业、人工森林(包括投资、土地需求、地理位置)、焦炭基高炉风口处喷吹木炭粉、采用木炭基生铁以实现焦炭高炉炉料的金属化,以及木炭生铁在炼钢中的利用。     

在西澳大利亚成功地生产金属硅

引言最近,在西澳大利亚州西南接近 Bunbu—ry 的 Kemerton,澳大利亚金属硅公司(SIMCOA)投产了一个两台炉子的具有现代水平的硅厂。尽管当初存在一些令人头痛的问题,但新建的工厂头一年的生产还是成功的且相比较而言没有出现什么问题。在初期能够取得成功的一个主要因素是所用原料的质量与稳定性,特别是公司在Kemerton 自己的木炭厂用废木材加工的高纯度、高反应性的木炭。在硅的生产中,木     

微波复合还原剂还原钛铁矿试验

采用微波加热和复合还原剂并添加添加剂对钛铁矿进行还原制备电焊条药皮原料。复合还原剂的使用提高了还原率、降低了杂质及有害元素的带入量、还大大降低了成本费用;添加剂(Na2CO3)使用降低了反应的活化能,强化了此钛铁矿的还原反应,缩短了反应时间;与常规加热方式相比,微波具有高效节能、绿色环保、强化反应等特点。在单因素试验条件还原温度1 150℃、还原时间100min下,试验研究了还原剂无烟煤和木炭对钛铁矿的还原能力;还原剂采用复合还原剂无烟煤、木炭的复合,在经试验验证及兼顾成本验证下,得出了复合还原剂无烟煤和木炭质量之比为11∶3,复合还原剂的使用可降低成本300~400元/t;试验还验证了添加剂Na2CO3(AR)的配入量和强化作用,结果表明,在最佳配量3%下可缩短反应时间约20min。     

生物质用于直接还原工艺研究

选取木炭和无烟煤作为还原剂,分别研究了还原温度、C/O、还原时间对球团金属化率的影响。此外,还采用XRD物相检测分析、对比无烟煤和木炭对球团的还原效果。研究结果表明:以生物质木炭作为还原剂具有与无烟煤相当的还原效果,当C/O相同时,配加生物质木炭的球团与配加无烟煤含碳球团相比获得球团金属化率差距并不明显,以木炭为还原剂实现含碳球团的直接还原是可行的;以木炭为还原剂时,1 200℃下,C/O=0.7,还原时间20 min时,球团金属化率可达80%以上。     

关于还原气中H2的脱除及木炭干馏的研究

本文对木炭干馏的方法及木炭干馏过程中的物理化学变化,尤其是气体成分的变化情况进行了研究。     

钢屑替代品用于硅铁生产的可行性分析

针对目前铁合金冶炼生产中钢屑原料短缺的问题,介绍了利用铁硅石、氧化铁皮、球团矿、废渣代替钢屑来冶炼硅铁的工艺,对其冶炼效果和经济可行性进行了分析。结果表明:在钢屑资源短缺的地区,利用钢屑替代品冶炼硅铁是可行的。     

Characterisation of coal–charcoal composite biocoke as a sustainable alternative for ironmaking

The partial substitution of coal by wood charcoal or other types of biomass for the production of metallurgical coke is catching the attention of the steelmaking industry worldwide because it generates less CO₂ in the industrial processes. The objective of this paper is to correlate the effect of the proportion of coal and wood charcoal on the mechanical strength and CO₂ reactivity in briquettes of mixtures of coal and wood charcoal. The briquettes were manufactured from mixtures of coal and 5, 10, 15, 20, 30, 40 or 50 wt-% of wood charcoal. Both materials were grounded and sieved until the particle size was less than 0.044?mm. The mixture was then pressed in a cylindrical die and heat-treated under a nitrogen flow from ambient temperature until 1373?K for 8 hours. Compressive strength and CO₂ reactivity tests were conducted on the samples. Optimal results of the compressive strength were obtained for additions of wood charcoal between 10 and 15 wt-%. For mixtures with wood charcoal contents above 5 wt-%, the CO₂ reactivity tests showed an increase in the reactivity compared to the briquettes of coal without the addition of wood charcoal.     

硅冶炼中还原剂改进与电炉容量扩大研究

用油团聚法处理的洗精煤与石油焦混合搭配替代工业硅冶炼木炭还原剂,探讨大容量矿热炉工艺特性,通过实验摸索最佳配比,实现了还原剂质优价廉的组合替代,减少森林破坏,节能降耗,产品质量和企业效益得到极大改善,各项技术指标较为良好。     

Decreased gas consumption of a fluidized bed furnace

The feasibility of utilizing a closed circulatory system to generate gases for a fluidized bed furnace was investigated with the primary concentrations of both economizing on the raw materials used for producing furnace atmospheres and decreasing the air pollution caused by exhaust gases. Air humidified with water vapor was first introduced into a charcoal furnace for causing a reaction with hot charcoal to form a carburizing atmosphere. This atmosphere was then introduced into a fluidized bed furnace to carburize steels. The exhaust gases from the fluidized bed furnace were recycled by repassing them through the hot charcoal layer in the charcoal furnace with a gas pump. The charcoal furnace and the fluidized bed furnace formed a closed circulatory system during the carburization of steels. Experiments were performed with various parameters of this system, including content of water vapor in the humid air, temperature of the charcoal, rate of recirculation of the atmosphere,etc. The effect of each parameter on the carburizing behavior in the fluidized bed furnace was investigated on the basis of the rate of carburization and the carbon potential of the atmosphere. The feasibility of applying this system to a fluidized bed furnace was assessed from the aspects of the fluidization of A1₂O₃ powder, the result of carburizing steel, and the rate of consumption of charcoal. The closed system employed in generating atmosphere was demonstrated by the experimental results to have enabled the fluidized bed furnace to operate normally and to have significantly decreased both the consumption rate of charcoal and the environmental pollution.     

Activated charcoal interrupts enteroenteric circulation of phenobarbital

The possibility of activated charcoal interrupting the enteroenteric circulation of phenobarbital was conducted in rabbits prepared by colectomy biliary drainage to block enterohepatic circulation. Fifty minutes after the administration of phenobarbital IV over ten minutes, activated charcoal (N = 7) or non-adsorbent gel (N = 8) were placed into the intestine at a dose of 4 g/kg. Blood was taken hourly for 5 h from the femoral artery and portal vein for the determination of phenobarbital concentration by the homogeneous enzyme immunoassay. The arterio-portal differences of phenobarbital concentrations were significantly greater in the animals treated with the charcoal at 2, 3 and 4 h after the treatment. There were significantly shorter plasma half lives of phenobarbital in the animals given charcoal (3.8 +/- 0.3 h vs 6.9 +/- 0.9 h, p < .02). This study provided evidence of significant enteroenteric circulation of phenobarbital which can be interrupted by the activated charcoal and removed by the mechanism of intestinal dialysis.     

Position statement: single-dose activated charcoal. American Academy of Clinical Toxicology; European Association of Poisons Centres and Clinical Toxicologists

In preparing this Position Statement, all relevant scientific literature was identified and reviewed critically by acknowledged experts using agreed criteria. Well-conducted clinical and experimental studies were given precedence over anecdotal case reports and abstracts were not usually considered. A draft Position Statement was then produced and subjected to detailed peer review by an international group of clinical toxicologists chosen by the American Academy of Clinical Toxicology and the European Association of Poisons Centres and Clinical Toxicologists. The Position Statement went through multiple drafts before being approved by the boards of the two societies and being endorsed by other societies. The Position Statement includes a summary statement for ease of use and is supported by detailed documentation which describes the scientific evidence on which the Statement is based. Single-dose activated charcoal should not be administered routinely in the management of poisoned patients. Based on volunteer studies, the effectiveness of activated charcoal decreases with time; the greatest benefit is within 1 hour of ingestion. The administration of activated charcoal may be considered if a patient has ingested a potentially toxic amount of a poison (which is known to be adsorbed to charcoal) up to 1 hour previously; there are insufficient data to support or exclude its use after 1 hour of ingestion. There is no evidence that the administration of activated charcoal improves clinical outcome. Unless a patient has an intact or protected airway, the administration of charcoal is contraindicated.     

Study on the adsorption of lanthanum(III) from aqueous solution by bamboo charcoal

The adsorption behaviors of La(III) ion on bamboo charcoal were investigated with various chemical methods and IR spectrometry. Parameters studied include the effects of pH, average particle size, initial ion concentration, contact time and temperature by batch method. The results showed that bamboo charcoal could remove La(III) ions effectively from aqueous solution. The loading of La(III) ions was strongly dependent on pH of the medium and the optimal adsorption condition was in HNO₃-TEA medium with pH value of 7.20. In the batch system, the modified bamboo charcoal exhibited the highest La(III) ion uptake as 120 mg/g at 298 K, at an initial pH value of 7.20. The adsorption kinetics were tested with Lagergren-first-order model and pseudo-second-order model. The adsorption data were conformed to the Langmuir and Freundlich isotherms, and the correlation coefficients had been evaluated. Thermodynamic parameters such as free energy (ΔG), which were all negative, indicated that the adsorption of La(III) ion onto bamboo charcoal was spontaneous and the positive value of enthalpy (ΔH) showed that the adsorption was endothermic in nature. Thomas model was applied to experimental column data to determine the characteristic parameters of column useful for process design. The characterization of both before and after adsorption of La(III) ion on bamboo charcoal was undertaken using IR spectroscopic technique. The results revealed that bamboo charcoal was a good choice as a biosorbent for the recovery of lanthanum from aqueous solution.     

Charcoal deposits in the esophageal and gastric mucosa

We report the case of a 75-yr-old woman referred for gastrointestinal endoscopy to investigate severe iron deficiency anemia. Black linear lesions were observed in the distal esophagus and stomach. Biopsies revealed aggregates of coarse black foreign material, which was later identified as charcoal. The patient's previous medical history included an antidepressant overdose 5 yr before the current admission. The patient had a gastric lavage, using a large bore orogastric tube, followed by the administration of activated charcoal. The patient had no other history of charcoal ingestion. We propose that the charcoal became entrapped in mucosal tears caused by the traumatic intubation 5 yr previously, causing the incidental mucosal tattooing seen at endoscopy.     

Study on the adsorption of lanthanum(Ⅲ) from aqueous solution by bamboo charcoal

The adsorption behaviors of La(Ⅲ) ion on bamboo charcoal were investigated with various chemical methods and IR spectrometry. Parameters studied include the effects of pH,average particle size,initial ion concentration,contact time and temperature by batch method. The results showed that bamboo charcoal could remove La(Ⅲ) ions effectively from aqueous solution. The loading of La(Ⅲ) ions was strongly dependent on pH of the medium and the optimal adsorption condition was in HNO3-TEA medium with pH value of 7.20. In the batch system,the modified bamboo charcoal exhibited the highest La(Ⅲ) ion uptake as 120 mg/g at 298 K,at an initial pH value of 7.20. The adsorption kinetics were tested with Lagergren-first-order model and pseudo-second-order model. The adsorption data were conformed to the Langmuir and Freundlich isotherms,and the correlation coefficients had been evaluated. Thermodynamic parameters such as free energy(ΔG) ,which were all negative,indicated that the adsorption of La(Ⅲ) ion onto bamboo charcoal was spontaneous and the positive value of enthalpy(ΔH) showed that the adsorption was endothermic in nature. Thomas model was applied to experimental column data to determine the characteristic parameters of column useful for process design. The characterization of both before and after adsorption of La(Ⅲ) ion on bamboo charcoal was undertaken using IR spectroscopic technique. The results revealed that bamboo charcoal was a good choice as a biosorbent for the recovery of lanthanum from aqueous solution.     

The influence of haemoperfusion on haemostasis and cellular constituents of the blood in the treatment of intoxications: a comparative study of three types of columns (Haemocol, Amberlite XAD-4, Gambro Adsorba 300 C)

The influence of haemoperfusion on blood-coagulation and cellular constituents of the blood was studied in three groups of patients. In four patients haemoperfusion was performed using a column containing acrylic-hydrogel coated activated charcoal (Haemocol), in five patients with a column containing uncoated XAD-4 nonionic polystyrene resin (Amberlite) and in five patients with a column containing cellulose coated activated charcoal (Gambro Adsorba 300 C). Perfusion was performed during 4 h with a flow of 300 ml/min. Before the start, 2 h after the start, at the end and 2 h after the end of the perfusion the haemoglobin concentration, haematocrit, leucocyte number, differential white cell count, thrombocyte number and heparin concentration were measured. Before the start and 2 h after the end prothrombin time, thrombin time, partial thromboplastin time, reptilase time, fibrinogen, prothrombin, factors V, VII, X, antithrombin III, bleeding time (Ivy), ethanol gelation test, fibrin split products and plasminogen were measured. The following conclusions can be drawn: haemoperfusion per se causes haemodilution; polystyrene resin causes in some patients a temporary reduction of the leucocyte number during haemoperfusion; polystyrene resin causes a significant reduction of thrombocyte number compared to coated activated charcoal; polystyrene resin and to a lesser extent acrylic-hydrogel-coated activated charcoal causes in some patients a prolongation of bleeding time probably by inducing alteration of thrombocyte function caused by release; polystyrene resin and probably also acrylic-hydrogel-coated activated charcoal causes an increased fibrinolytic activity without signs of disseminated intravascular coagulation.     

Cholestyramine as an adsorbent in acute lindane poisoning: a murine model

STUDY OBJECTIVES: To compare the effectiveness of single-dose cholestyramine versus single-dose activated charcoal in preventing clinical toxicity after acute lindane ingestion. DESIGN: CD-1 mice received lindane by enteral (gavage) and parenteral (intraperitoneal) routes, followed by enteral administration of either cholestyramine (2.25 g/kg) or activated charcoal (2.25 g/kg), with subsequent observation for convulsions and death. MEASUREMENTS: The doses of lindane at which 50% of mice developed convulsions (CD50) and at which 50% of mice died (LD50) were established and compared among control, charcoal-, and cholestyramine-treated groups. RESULTS: For lindane administered by gavage, the differences in the CD50 and LD50 between the control and the activated charcoal groups were not statistically significant. However, a significant difference did exist in both the CD50 and the LD50 between the group receiving cholestyramine and the control group and between the cholestyramine and activated charcoal groups. After IP administration of lindane, the difference in CD50 or LD50 among control, activated charcoal, or cholestyramine groups was not significantly different. CONCLUSION: In the murine model, cholestyramine is more effective than activated charcoal in preventing absorption of lindane, thus preventing convulsions and death. These data support the need for clinical studies to determine whether cholestyramine may be a more effective treatment than activated charcoal for acute lindane ingestions in human beings.