Accuracy analysis of iron content of galvanized coating using an X-ray fluorescence spectrometer with an L-spectrum

The accuracy(repeatability and reproducibility) of the iron content analysis of galvanized coating using an X-ray fluorescence spectrometer with an L-spectrum is not better than that of flame atomic absorption spectrometry, sometimes it exceeds the quality control limit.Influences, such as current, voltage, equipment(internal circulating water, 10%CH4+90%Ar, and vacuum) checking, instrument monitoring, sample cleaning, and oper-ators, were investigated by means of 6-sigma and lean operations to improve accuracy.

Response of Iron Content in Milled Rice to Nitrogen Levels and Its Genotypic Differences

To investigate the effect of nitrogen （N） level on iron （Fe） content in milled rice, a field experiment was carried out under three N application levels including 0, 150 and 300 kg/hm2 by using 120 rice genotypes. In addition to the genotypic differences of iron content in milled rice, grain yield, 1000-grain weight and N content in grains under the same N level, there were also variations in the response of Fe content in milled rice to N levels. Based on the range and variation coefficient of Fe content in milled rice under the three N levels, the response of Fe content in milled rice to N levels could be classified into four types including highly insensitive, insensitive, sensitive and highly sensitive types. A significant quadratic correlation was found between the Fe content in milled rice and 1000-grain weight or the N content in grains. However, no significant correlation between the Fe content in milled rice and grain yield was detected. In conclusion, there are genotypic differences in the effects of N levels on Fe content in milled rice, which is favorable to breeding of Fe-rich rice under different N environments. Furthermore, high yield and Fe-rich rice could be grown through the regulation of nitrogen on Fe content in milled rice, 1000-grain weight and N content in milled rice.

Application of communication program between atomic absorption spectrometer and electronic balance for iron content determination of the galvanneal coating

At present,iron content in a galvanneal coating is determined by an atomic absorption spectrometer(AAS)in Baosteel.The mass of a sample is recorded by operators two times on paper,then the mass of the coating is manually calculated and input in a computer.With the aid of a communication program between an AAS and an electronic balance(EB),the above process can be modified.First,the mass of a sample is sent to a computer by the EB.Second,the mass of the coating is calculated by the computer automatically.Finally,the iron mass is uploaded to the communication program,and the iron content can also be calculated automatically.As such,the modified process is more efficient.

Study on determination method of iron content in galvanized coating of zinc-iron alloy

The iron content in the galvanized coating of zinc-iron alloy was determined by atomic absorption spectrometry and two kinds of X-ray fluorescence(XRF)methods.Results show that the chemical method exhibits the highest accuracy.However,this method presents low detection efficiency and is thus unsuitable for production quality control.Fundamental parameter and empirical coefficient methods in XRF can be used for the quality control of iron content in the galvanized coating of zinc-iron alloys.The repeatability of the two XRF methods was 0.2%and 0.4%,respectively,which were better than that of the chemical method(0.6%).However,the two XRF methods have their own limitations.The accuracy of the two XRF methods depends on the process stability of different units and may be poorer than that of the chemical method.Thus,the use of the two XRF methods should be carefully restricted.

Determination of Iron Content of Three Common <i>Acacias</i>of Sudan

The amount iron content of the extracts and samples of Acacia species was determined. Since the iron hinders the process of retanning leather, iron content is determined by wet digestion method and atomic absorption spectrophotometry. The iron contents of bark extract of Acacia nilotica, Acacia senegal and Acacia seyal were 0.0044%, 0.0040% and 0.0029% respectively. In contrast, the iron content of bark extract of the three species of Acacia had lower percentage compared to that of Mimosa (Acacia mearnsii) (0.0047%), which was imported from Kenya. The iron content presented in leaves, barks, mature and immature fruits of Acacia species were determined by the same analytical methods. Bark and mature fruits of Acacia nilotica had the highest and equal percentage (0.1450%). The percentage of iron content of leaves and bark of Acacia seyal had equal percentage (0.0750%), while the bark of Acacia senegal had much lower percentage (0.0375%).

Effect of content and spin state of iron on electronic properties and floatability of iron-bearing sphalerite:A DFT+U study

Iron is an impurity widely occurred in sphalerite,and its effect on sphalerite flotation is complex.In this work,the effects of iron content and spin state on electronic properties and floatability of iron-bearing sphalerite are comprehensively studied using density functional theory Hubbard U(DFT+U)calculations combined with coordination chemistry flotation.The band gap of ideal sphalerite is 3.723 eV,and thus electron transition is difficult to occur,resulting in poor floatability.The results suggest the band gap of sphalerite decreases with increasing iron content.For low iron content,the decreased band gap facilitates electron transition;at this case,Fe^(2+)in a high-spin state possesses oneπelectron pair,which can form a weakπ-backbonding with xanthate,causing increasing floatability.However,for medium and high iron-bearing sphalerite,with the further decrease of band gap,Fe^(2+)is oxidized to Fe^(3+)due to electrochemical interaction,and henceπ-backbonding is eliminated,leading to lower floatability of iron-bearing sphalerite,which is consistent with the flotation experimental results.This work could give a deeper understanding of how sphalerite flotation behaviors are affected by iron content.

FeCe nanocomposite with high iron content as efficient catalyst for generation of COx-free hydrogen via ammonia decomposition

FeCe nanocomposite catalysts with different iron contents were synthesized by a facile co-precipitation method.The as-prepared materials were characterized by various techniques including powder X-ray diffraction(XRD),N2 adsorption/desorption and high-resolution transmission electron microscopy(HRTEM).Catalyst with the highest iron content(90 FeCe) shows the best activity for the hydrogen generation via ammonia decomposition.83% NH3 conversion is achieved at 550℃ and nearly full conversion of NH3 is realized at 600℃ with a GHSV of 24000 cm3/(gcat·h).The large content and small size crystal particles of iron species are responsible for the good catalytic performance.Temperatureprogrammed reduction by hydrogen(H2-TPR) was performed to investigate the interaction between cerium and iron species.It is found that slight cerium can exert strong interaction with iron compound thus effectively prevent the self-aggregation of active iron species,so as to improve the catalytic activity for ammonia decomposition.

Effect of decarburization annealing temperature and time on the carbon content, microstructure, and texture of grain-oriented pure iron

In this study,the effect of decarburization annealing temperature and time on the carbon content,microstructure,and texture of grain-oriented pure iron was investigated by optical microscopy and scanning electron microscopy with electron-backscatter diffraction. The results showed that the efficiency of decarburization dramatically increased with increasing decarburization temperature. However,when the annealing temperature was increased to 825°C and 850°C,the steel's carbon content remained essentially unchanged at 0.002%. With increasing decarburization time,the steel's carbon content generally decreased. When both the decarburization temperature and time were increased further,the average grain size dramatically increased and the number of fine grains decreased; meanwhile,some relatively larger grains developed. The main texture types of the decarburized sheets were approximately the same: {001}<110> and {112~115}<110>,with a γ-fiber texture. Furthermore,little change was observed in the texture. Compared with the experimental sheets,the texture of the cold-rolled sheet was very scattered. The best average magnetic induction(B_(800)) among the final products was 1.946 T.

STUDY ON THE VARIATION MECHANISM OF CARBON CONTENT OF LIQUID IRON IN MELTING GASIFIER

This paper studied the changing principles of carbon content in direct reduction iron (DRI) and liquid iron in the COREX melting gasifier. Under the normal working conditions of experimental equipment, liquid nitrogen was poured into the melting gasifier from its tuyere to cool down quickly. And then seven cross sections were made to study the carburization reaction and its characteristics of the solid iron and the liquid iron, and also the reaction of carbon between the slag and the metal. According to the results, the influences of the thickness of the semi-coke layer and the temperature on the carbon content of liquid iron in the COREX melting gasifier were confirmed.

Calculation of carbon content of austenite during heat treatment of cast irons

The austenitizing temperature controls the carbon content of the austenite which,in turn,influences the structure and properties of cast irons after subsequent cooling to room temperature.In this paper,for a cast iron with known silicon content,a formula of calculating austenite carbon content at a certain austenitizing temperature was developed.This relationship can be used to more accurately select carbon content of austenite or austenitizing temperature to produce desired properties after subsequent cooling to room temperature.

Effects of carbon content and solidification rate on thermal conductivity of grey cast iron

The thermal conductivity or diffusivity of pearlitic grey irons with various carbon contents is investigated by the laser flash method. The materials are cast in controlled thermal environments and produced in three dissimilar cooling rates. The cooling rate together with the carbon content largely influence the thermal conductivity of grey iron. Linear relationships exist between the thermal conductivity and the carbon content,the carbon equivalent and the fraction of former primary solidified austenite transformed into pearlite. The work shows that optimal thermal transport properties are obtained at medium cooling rates. Equations describing the thermal conductivity of pearlite,solidified as pre-eutectic austenite,and the eutectic of grey iron are derived. The thermal conductivity of pearlitic grey iron is modeled at both room temperature and elevated temperature with good accuracy.

Influence of Fe Content on Tool Galling in Ironing Aluminum Beverage Cans

Insoluble constituents in 3104 alloy for beverage cans manufacturing play an important role in deep ironing process. This paper studies the effect of Fe content in the alloy on volume fraction of the constituents Al6(Fe, Mn)3 and Al12(Fe, Mn)3Si and its influence on ironing die pickup. It is shown that with Fe content increase, the amount of these constituents rises that helps prevent tool galling. Trials made at a can plant showed less ironing die changeovers at bodymakers. The optimum Fe content for aluminum can production can be considered between 0.47% and 0.53% that corresponds to 2.0% - 2.3% of insoluble constituent volume fraction. Greater amounts than this cause problems with excessive constituent particle formation and earing;smaller amounts result in increased ironing die galling.

芜菁多糖铁配合物的合成工艺研究

目的研究芜菁多糖铁(Ⅲ)[BP-Fe(Ⅲ)]配合物的合成工艺。方法以三氯化铁和芜菁多糖为反应物,合成一种芜菁多糖铁(Ⅲ)配合物;采用单因素法系统研究pH、反应时间、温度、枸橼酸钠与多糖质量比4个因素对BP-Fe(Ⅲ)配合物合成量的影响;采用正交实验筛选BP-Fe(Ⅲ)配合物的最优合成工艺;采用UV法测定BP-Fe(Ⅲ)配合物中的铁含量,进行铁离子特征反应实验;对BP-Fe(Ⅲ)配合物和芜菁多糖进行红外光谱表征。结果正交实验结果显示BP-Fe(Ⅲ)配合物的最优合成工艺条件为枸橼酸钠和芜菁多糖质量比2∶1,反应时间180 min,反应液pH=6,反应温度60℃,该条件下铁含量为4.53%,对BP-Fe(Ⅲ)配合物中铁含量影响顺序为:枸橼酸钠和多糖质量比(A)>反应液pH值(B)>反应时间(C)>反应温度(D);铁离子特征反应实验结果表明芜菁多糖与铁络合成稳定的配合物;红外光谱图显示芜菁多糖与铁形成的稳定配合物基本结构无较大变化。结论本方法操作简单,成本低,适用于多糖铁配合物的合成。

Effects of Fe content on the microstructure and properties of CuN i10FeM n1 alloy tubes fabricated by HCCM horizontal continuous casting

Heating-cooling combined mold（HCCM） horizontal continuous casting technology developed by our research group was used to produce high axial columnar-grained CuN i10 FeM n1 alloy tubes with different Fe contents. The effects of Fe content（1.08wt%–2.01wt%） on the microstructure, segregation, and flushing corrosion resistance in simulated flowing seawater as well as the mechanical properties of the alloy tubes were investigated. The results show that when the Fe content is increased from 1.08wt% to 2.01wt%, the segregation degree of Ni and Fe elements increases, and the segregation coefficient of Ni and Fe elements falls from 0.92 to 0.70 and from 0.92 to 0.63, respectively. With increasing Fe content, the corrosion rate of the alloy decreases initially and then increases. When the Fe content is 1.83wt%, the corrosion rate approaches the minimum and dense, less-defect corrosion films, which contain rich Ni and Fe elements, form on the surface of the alloy; these films effectively protect the α-matrix and reduce the corrosion rate. When the Fe content is increased from 1.08wt% to 2.01wt%, the tensile strength of the alloy tube increases from 204 MPa to 236 MPa, while the elongation to failure changes slightly about 46%, indicating the excellent workability of the CuNi10FeMn1 alloy tubes.

湖北鄂东某陶瓷用长石除铁增白选矿试验研究

为合理高效开发湖北鄂东某陶瓷用长石矿资源,基于原矿工艺矿物学分析,进行除铁增白试验研究。结果表明,原矿中主要有用矿物为斜长石和钾长石,脉石矿物为石英、石榴子石、云母、磁铁矿、褐铁矿及少量的赤铁矿,其中含铁杂质是影响白度的主要因素。采用“水洗脱泥-磁选脱铁”联合流程,可以获得产率为97.16%的长石精矿,其铁杂质含量从1.105%降至0.295%,白度相应由46.11%提升至64.92%,同时Na_(2)O与K2O总量略有提升,精矿产品各项指标达到QB/T 1636-2017《日用陶瓷用长石》行业标准钠长石合格品的要求,实现了该长石矿的高附加值利用。

高铁低品位红土镍矿酸浸工艺研究

研究了用硫酸从印尼某高铁低品位红土镍矿中加压酸浸镍、钴、铁,并探讨了浸出渣中铁品位变化及常压、加压下的浸出动力学。结果表明:在酸矿比260 kg/t、温度250℃(对应水蒸气压力4.0 MPa)、液固体积质量比3/1、搅拌速度300 r/min、粒度100目、反应时间1 h条件下,镍、钴、铁浸出率分别为98.1%、98.3%、4.7%,铁品位可达51.3%;加压和常压下,镍、钴浸出过程均符合界面化学反应控制的收缩核模型,加压下反应活化能分别为116、91 kJ/mol,常压下反应活化能分别为41、53 kJ/mol;常压下主要是针铁矿的浸出,高压下主要是铬铁矿、磁铁矿等矿相的浸出。

双终点-自动电位滴定法测定镍基高温合金中铁

建立双终点-自动电位滴定法测定镍基高温合金中铁含量的测定方法。以铂电极为指示电极,重铬酸钾标准滴定溶液为滴定剂。试料采用盐酸、硝酸和高氯酸进行溶解,用氨水将铁和共存干扰元素分离。在约10%盐酸酸度下,以钨酸钠为指示剂,用三氯化钛调至溶液变蓝,在设定的滴定程序和参数下,用重铬酸钾标准滴定溶液滴定至出现两个等当点,两个等当点的体积差为铁消耗的滴定体积,计算铁含量。考察了仪器参数、滴定介质酸度、共存元素干扰情况和干扰元素分离条件。在最优的实验条件下,对有证标准物质进行测试,并进行方法比对,允许差满足HB 5220.29—2008的要求。方法的相对标准偏差为0.16%~0.44%。方法避免了人为判断终点带来的误差,减少了目视滴定中滴定过量三氯化钛的步骤,试验操作简单,准确度高,精密度好,能够满足镍基高温合金中铁元素的测定。

Effect of welding process methods on the regularity of iron element in copper/steel deposited layer

Copper was surfaced on the Q235 substrate by shielded metal arc welding （SMAW） and tungsten inert-gas （TIG） arc welding, the regularity of iron element in deposited metal was analyzed by metallograph, scanning electron microscopy and energy disperse spectroscopy. The results indicate that with the increase of SMA W welding speed, the iron content decreases and the granular or spherical iron becomes more bulky in the overlay. The iron content obviously decreases with the increase of surfacing layers＇ numbers in multilayer welding because of the substrate dilution. On the third layer, the microstrueture of deposited metal is single-phase e-copper. Under the influence of welding methods, the granular or spherical crystal morphology is more likely to form in SMAW for the more divergent arc heat, but is dendrite in TIG welding because of centralized arc energy.