Recovery of heavy metals from electroplating sludge and stainless steel pickle waste liquid by ammonia leaching method

A coordinative disposal process for treatment of electroplating sludge and stainless steel pickle waste liquid containing Cu, Ni, Zn, Cr and Fe etc., has been developed to recover valuable metals and to eliminate pollution. The recovery of Cu, Ni, Zn and Cr is 94%, 91%, 90% and 95%, respectively. The ammonia was recycled by the simplified process of CaO caustic distillation. The precipitated product of Cu, Ni and Zn obtained from caustic distillation of ammonia was separated by extraction or high\|pressure hydrogen reduction in an autoclave. The qualified metal salt products were obtained through extraction. The rich chromium residue from coordinative disposal was subjected to recover Cr by hydrothermal oxidation in NaOH medium and Fe\-3O\-4 was synthesized by wet methods from the residue produced by extracting Cr. Cr was a stable chemical fixed in Fe\-3O\-4 and harmless. The recovery process has been used in a pilot plant with sludge production capacity of 2000 t/a.

Analysis of edge microstructural characteristics and stamping formability of low carbon pickled steel sheets

The microstructural characteristics and formability at the edges of low carbon pickled steel sheets have been investigated based on the generation of earing and cracking defects while drawing. The microstructure of the edge features coarse grains and mixed sized grains. The strength of the sheet edge is slightly lower than that at the center. Besides, the formability is obviously worsened. The plastic strain ratios along the longitudinal and transverse orientations are 0.31 and 0.6, respectively, with distinct anisotropy. The plastic strain ratio at the edge is obviously lower than that at the middle of the steel sheet. The observed microstructural characteristics and mechanical properties at the edge of the steel sheet can be attributed to the lower rolling temperature in the two-phase region of pro-eutectoid ferrite and austenite. These differences in microstructure and mechanical properties at the edge of the steel sheet lead to the generation of earing and cracking defects while drawing. The microstructure and mechanical properties at the edge of low carbon pickled steel sheets can be improved via the optimization of the rolling process and the adjustment of chemical composition.

Screening and Characterization of Nitrite Degrading <i>Lactobacillus plantarum</i>in Chinese Traditional Pickles

A Gram-positive, non-spore, round ended, straight rod Lactic acid bacteria were screened. The strain was screened out from the traditional pickle jar in Yutang soy sauce garden of Jining. In order to degrade the nitrate content in the fermentation process of traditional pickles and improve the quality of pickles, it is necessary to screen out nitrite degrading strains from pickles, and preliminarily locate nitrite reductase, and find out the most suitable pH, temperature and culture time to degrade nitrite. Lactobacillus plantarum was screened by MRS medium in advance. After 48 hours of culture in a shaking table with Bacillus subtilis, the cell components were separated by centrifugation, wall breaking and other operations. After 20 hours at 30°C, the content of nitrite in each component was determined by the naphthalene ethylenediamine hydrochloride method (NIR). The culture conditions were as follows: inoculation amount 3%, 6%, 9%, 12%, 15%;salinity 2%, 4%, 6%, 8%, 10%;temperature 15°C, 20°C, 25°C, 30°C, 35°C for 20 h. The results showed that the best degradation effect of nitrite was obtained under the conditions of 9% inoculum, salinity 5% and 30°C. Under the conditions of 9% inoculum, 5% salinity and 30°C for 5 h, 10 h, 20 h, 48 h, 66 h and 78 h, the results showed that the degradation amount gradually increased with the extension of time, and gradually maintained a stable state. Lactobacillus plantarum JBA-3 is a new type of lactic acid bacteria which can degrade nitrite and produce nitrite reductase.

Development and Optimization of Protein Rich Germinated Bengal Gram Pickle Using Response Surface Methodology

Bengal gram on germination has high nutritive value in terms of protein, fibre and minerals yet it has very low shelf life at room temperature, hence to enhance the shelf life of germinated Bengal gram, a value added product can be developed in the form of Pickle with vinegar, oil and salt as preservatives. To optimize the quantity of ingredients to be added, Response Surface Methodology was used. Statistical software Stat-Ease was used for statistical and graphical analysis of the experimental data. It was found that the sensory scores were 7.2, 8.4, 7.8 ＆ 7.7 for color, flavor, texture and overall acceptability corresponding to optimum conditions.

Study on Nutrients and Texture of Pickled Huangzhou Radish

[Objectives]The changes in the nutrient contents and texture of pickled Huangzhou radish with pickling time were studied to further improve its edible value and improve its sensory evaluation.[Methods]Huangzhou radish as a raw material was pickled,and exploration was conducted through the following aspects:with the extension time of pickling time,the changes in nutrient contents such as reducing sugars,free amino acids and ascorbic acid were detected in pickled Huangzhou radish,and the changes in the texture characteristics of pickled Huangzhou radish such as hardness,viscosity,elasticity,recoverable deformation,compression power and chewiness were detected.[Results]As the pickling time became longer,the reducing sugar content in pickled Huangzhou radish gradually increased,and when the pickling time exceeded 13 d,the reducing sugar content showed a downward trend;the ascorbic acid content gradually decreased,and the decreasing rate was relatively lower after the pickling time exceeded 7 d;and the amino acid content first increased and then decreased,and when the pickling time exceeded 13 d,the content exhibited basically no change.The hardness of the radish gradually decreased;the viscosity first decreased and then slowly increased;the recoverable deformation first increased and then decreased;the elasticity first increased and decreased;and the chewiness first increased and then decreased.Through this experiment,it is concluded that the pickled Huangzhou radish has richer nutrients and the best taste when the pickling time is 7-10 d.[Conclusions]This study provides a theoretical reference for producing and processing pickled Huangzhou radish,improving the quality of pickled Huangzhou radish and increasing the nutritional value of the product.

Effects of Pickled Cabbage Water on Production Performance of Laying Hens

[ Objective] To study the effects of pickled cabbage water on production performance of laying hens, and provide a scientific basis for the application of the pickled cabbage water used as the microbial drinking water preparation in production of laying hens. [Method] A total of 2 520 laying hens at the age of 35 weeks and with the same feeding conditions were randomly divided into four groups. They were respectively fed four kinds of drinking water preparations including pickled cabbage water, enrofloxacin, Bacillus cereus and normal water. The mortality, egg laying rate and elimination rate were recorded. The experiment lasted for 8 weeks. [ Result] In the pickled cabbage water group, the mortality and elimination rate of laying hens were decreased, and the egg laying rate was increased significantly （P 〈 0.05）. The enrofloxacin and Bacillus cereus water preparations had effects on the production performance of laying hens, and the effects were not significant. [ Conclusion] The pickled cabbage wa- ter can regulate the intestine microenvironment of laying hens. It also promotes the survival rate and egg production and enhances the disease resistance of laying hens. Therefore, the pickled cabbage water can be used for laying hens production as microbial drinking water preparation.

A Comment on Katherine Mansfield＇s A Dill Pickle

Katherine Mansfield is a world famous woman master of short stories in English literature. Her stories are sensitive revelations of human behaiour in quite ordinary situations, through which we can glimpse a powerful, and sometimes cruelly pessimistic view of life. A Dill Pickle is one of her short stories published in 1917, describing the encounter between a young woman and a young man who have been lovers six years ago and their lost love and changes over the years. Short as it is, it is really worth our earful analysis and appreciation. This paper will comment on this short story from the following two aspects： a commont on the theme of the story; a comment on the writing technique of the story. The paper conludes that romantic love is dependent upon circumstances and the convergence of certain character traits at a particular time.

Liubiju Sauce and Pickle Shop

The Liubiju Sauce and Pickle Shop was established in 1531, the ninth year of the Jiajing Emperor’s rein of the Ming Dynasty.It is a famous old enterprise of Beijing. The shop’s founder was Mr. Zhao from Linfin County, Shanxi Province. The pickled products are made of selected vegetables and other ingredients to retain the sauce aroma and special flavour and delicious taste. The prod-

基于二氧化铈/羟基氧化铁纳米酶的比色分析法快速检测泡椒凤爪中过氧化氢

采用水热法合成二氧化铈(CeO_(2))修饰的羟基氧化铁(FeOOH),得到纳米材料CeO_(2)/FeOOH。CeO_(2)/FeOOH具有类过氧化物酶活性,可以催化过氧化氢(H_(2)O_(2))分解产生羟自由基(·OH)和超氧阴离子自由基(O2-·),将3,3’,5,5’-四甲基联苯胺(3,3’,5,5’-tetramethylbenzidine,TMB)氧化为蓝色的氧化TMB(oxidized TMB,ox-TMB)。基于此,构建基于CeO_(2)/FeOOH纳米酶的H_(2)O_(2)比色传感器。结果表明:该比色传感器对H_(2)O_(2)显示出高灵敏度响应,检测限为3.92μmol/L,检测范围为10~1000μmol/L。此外,该传感器可用于泡椒凤爪中H_(2)O_(2)的快速检测,其中,H_(2)O_(2)加标回收率为90.59%~93.42%,相对标准偏差≤4.25%,具有灵敏、准确、快速和简便等优势。

Research into Technology of Bao Steel's Pickling Tension Leveler

According to the survey of Bao Steel's pickling tenstion leveler,the technology of the tension leveler is analysed systematically.In order to solve the problem which hinders the production,the given technological parameters of this leveler have been improved and good results achieved.

Characterization and recycling of nickel- and chromium-contained pickling sludge generated in production of stainless steel

Pickling sludge generated during the neutralization of pickling wastewater with calcium hydroxide in stainless steel pickling process was characterized using X-ray fluorescence spectrometry, X-ray diffractometry, scanning electron microscopy, thermogravimetry and differential scanning calorimetry, etc. The major compositions of pickling sludge are CaF2, CaSO4, Me（OH）, （M： Fe, Cr, Ni）, and the content of CaF2 is high in the sludge. The melting point of pickling sludge is about 1350℃ and the viscosity is about 0.14 Pa.s at 1450 ℃, which are comparatively lower than those of normal refining slag. After heat treatment, the contents of sulfur and fluorine in the pickling sludge were reduced, confirming the thermal decomposition of sulfate in the sludge. Fluorine in the sludge is reduced by the gaseous SiF4 and A1F3 generated through the reactions of CaF2 with SiO2 and Al2O3. The preliminary results from the reduction test indicate that the sulfur content in the steel is not affected by the presence of sulfur in the sludge. The recovery of nickel is about 40%, and the chromium content changes marginally due to the protective atmosphere under the reduction condition of chromic oxide. The pickling sludge is a potential auxiliary material for the production of stainless steel.

Two-stage treatment process of pickling wastewater in the cold-rolling production of stainless steel

Based on the characteristics of pickling wastewater in the cold-rolling production of stainless steel, a new processing route, featuring source sludge reduction, wastewater two-stage treatment, heavy metal-contained sludge and calcium salt sludge separating recovery, was proposed. As shown by the research results, after the two-stage process treatment, the effluent water can steadily reach the emission standards, the sludge yield can be decreased by more than 8% ; within the heavy metal-contained sludge, the recovery rates of Fc,Cr and Ni can either reach or surpass 95% ,and the total content ofF and S can drop to around 3%. Therefore,the sludge in the front part can be used as ferric dust. In the calcium salt sludge ,the recovery rate of F can either reach or surpass 85% ,and the total contents of Fe,Cr and Ni can fall below 0.5%. So the sludge in the rear part can be used as fluorgypsum or fluorite. Meanwhile,the results of the analysis on heavy metals leaching toxicity and morphologic distribution indicate that the two kinds of sectionalized sludge are not classified as hazardous wastes, which have a stable behavior and better utilization values compared with the former mixed- sludge.

Synthesis of Fe_3O_4 Magnetic Powder from Spent Pickling Liquors

Spent pickling liquors pose a serious environmental problem in most industrialized countries, mainly owing to their corrosive properties and their ferrous iron and hydrochloric acid content. In this paper, spent pickling liquor was used as an inexpensive raw material to prepare Fe304 magnetic powder via an oxidation method. Being able to recover the dissolved iron from spent pickling liquors would not only salvage a valuable material but also render the effluent environmentally benign. The structure of the Fe_3O_4 magnetic powder was characterized by X-ray diffraction. The morphology and size were characterized by scanning electron microscopy and transmission electron microscopy. Their magnetic properties were tested at room temperature by a vibrating sample magnetometer. In addition, the saturation magnetization of Fe_3 O_4 products can be further enhanced to 96.1 emu/g after purification.

Acid-pickling plates and strips speed control system by microwave heating based on self-adaptive fuzzy PID algorithm

Double self-adaptive fuzzy PID algorithm-based control strategy was proposed to construct quasi-cascade control system to control the speed of the acid-pickling process of titanium plates and strips. It is very useful in overcoming non-linear dynamic behavior, uncertain and time-varying parameters, un-modeled dynamics, and couples between the automatic turbulence control (ATC) and the automatic acid temperature control (AATC) with varying parameters during the operation process. The quasi-cascade control system of inner and outer loop self-adaptive fuzzy PID controller was built, which could effectively control the pickling speed of plates and strips. The simulated results and real application indicate that the plates and strips acid pickling speed control system has good performances of adaptively tracking the parameter variations and anti-disturbances, which ensures the match of acid pickling temperature and turbulence of flowing with acid pickling speed, improving the surface quality of plates and strips acid pickling, and energy efficiency.

Does acid pickling of Mg-Ca alloy enhance biomineralization?

The mechanical and physical properties of biodegradable magnesium(Mg)alloys make them suitable for temporary orthopaedic implants.The success of these alloys depends on their performance in the physiological environment.In the present work,surface modification of Mg-Ca binary alloy by acid pickling for better biomineralization and controlled biodegradation is explored.The corrosion rates of nitric and phosphoric acid treated samples were analysed by conducting electrochemical corrosion tests.In vitro degradation behaviour was studied using immersion test in simulated body fluid(SBF).The sample surfaces were characterized using scanning electron microscope(SEM),energy dispersive X-ray spectroscopy(EDS),Fourier transform infrared spectroscopy(FTIR)and X-ray photoelectron spectroscopy(XPS).It is seen that acid pickling leads to significant improvement in biomineralization and develop in situ calcium phosphate(Ca P)coating on the sample surfaces.In addition,the treated samples recorded a reduced degradation rate in the SBF compared to untreated samples.Thus,acid pickling is suggested as an effective surface treatment method to tailor the biomineralization and degradation behaviour of the Mg-Ca alloy in the physiological environment.

Innovative surfactant of Gemini-type for dissolution mitigation of steel in pickling HCl medium

A new surfactant of Gemini-type,N,N'-((phthylbis(oxy))bis(ethane-2,1-diyl))bis(N,N-dimethyldodecan-1-aminium bromide)is prepped&confirmed.The dissolution suppression impact of the new compound on steel is performed in 1 mol·L^(-1)HCl environment by means of chemical and electrochemical methods.The prepared surfactant is an agreeable dissolution inhibitor for steel.The mitigation efficacy rises with the quantity of the compound.The surfactant belongs to inhibitors of mixed-type.The adsorption of the synthesized compound followed the Langmuir's model.The negative magnitudes of bothΔG_(ads)^(θ) andΔH^(adsθ)indicate that the adsorption process proceeds from its own accord and exothermic.The mechanism of adsorption is elucidated by scanning microscopy.It is established that the transfer resistance(R_(ct))value rose,where the value of the phase element(CPE)reduced with the amount of synthesized inhibitor.According to the experimental data arrived by surface tension measurements,the prepared compound is a powerful active agent at the air/water boundary.

One-step pickling-activation before magnesium alloy plating

A one-step pickling-activation process was proposed as an environmental friendly pretreatment method in phosphate-permanganate solution before electroplating on magnesium alloys. The effects of pickling-activation on qualities of coating were assessed by adhesion and porosity testing of copper plating. The interfacial reactions between specimen and solution were analyzed with SEM,EDX and XRD. The results show that the developed process of pickling-activation can equalize the potentials on substrate surface. The compacted zinc film can be obtained by zinc immersion after treating magnesium alloy in the pH 4-6 phosphate-permanganate solution for 3-5 min. The adhesion and corrosion resistance of copper plating are enhanced. The one-step pickling-activation can replace the existing two-step process of acid pickling and activation which contains a great deal of chromium and fluorine. The procedure of surface pretreatment is simplified and the production environment is improved.

Study on the simulated pickling of 443NT medium chrome ferritic stainless steel

The oxide scale structure of 443NT hot-rolled strips was analyzed. The pickling of 443NT stainless steel was simulated via the 6σ experimental design. The results indicate that parabolic relations exist between the pickling scores and some of the pickling influencing factors, such as the nitric acid density, the hydrofluoric acid density and the pickling temperature. Effective pickling of 443NT can be achieved by controlling the pickling processing parameters with the HNO3 density ranging from 80 g/L to 180 g/L ,the HF density from 20 g/L to 40 g/L and the pickling temperature from 45 ℃ to60 ℃.

Mechanism underlying the formation of cloud-shaped defects in 304 stainless steel after hot-rolled annealing and pickling

It is highly imperative to understand the mechanism underlying the formation of cloud-shaped defects in stainless steel to reduce the defect incidences. This study investigated the defect microstructure by SEM, simulated pickling in the laboratory, and performed structure analysis of oxide scales after hot rolling. Results show that the cloud-shaped defects in 304 No. 1 surface （after hot-rolled annealing and pickling） cause the pickling chromatic aberration between the honeycomb-shaped grains of the Cr-depleted layer and the smooth grains of the stainless steel matrix, which is formed in the case of insufficient pickling. The chromatic aberration is related to the uneven oxide scales formed before pickling. With the improvement of pickling capacity, it is possible to completely pickle the Cr-depleted layer and eliminate the cloud-shaped defects.

A new acid pickling process for copper alloys

The cleaning process of removing oxides on the surface of copper alloy sheetswas investigated systematically. Through optimizing, a perfect process was selected that is fit forremoving oxides on the surface. By acid pickling, all kinds of copper oxides are removedcompletely, furthermore, no poisonous gases are given out and a smooth and clean surface of copperalloys is obtained. At present, the process is applied successfully in the copper-processingindustry.