用生产钛白的副产物绿矾处理含铬废水
55
用生产钛白的副产物绿矾处理含铬废水
杨明平,傅勇坚,李国斌
(湖南科技大学化学化工学院,湖南湘潭411201)
[摘 要] 处理含铬废水的方法较多,但效果不太理想。以生产钛白的副产物绿矾作为还原剂,通过氧化还原、中和沉淀、分离等步骤处理含铬废水,研究了绿矾处理含铬废水的工艺条件。结果表明,按铁铬比20、氧化还原反应的p H 值3.5~4.0、氧化还原时间15~20m in 和中和反应的p H 值6.5、中和反应时间10~15m in 的工艺条件,对含C r 6+
35mg /L 左右的废水进行处理,铬的去除率达到
97.4%以上,处理后的水样中C r 6+
含量小于0.50mg /L 、总铬含量小于1.0m g /L ,达到国家排放标准。
[关键词] 废水处理;含铬废水;绿矾;氧化还原反应;中和沉淀反应
[中图分类号]X781.1 [文献标识码]B [文章编号]1001-1560(2005)06-0055-03
[收稿日期] 20050326
0 前 言
在含铬工业废水中,六价铬的最高允许排放浓
度为0.5m g /L 和总铬为1.5m g /L [1]
。目前,含铬废水的治理方法比较多,如化学还原法、电化学还原法、离子交换法、蒸发回收法、活性炭法等
[2~5]
,
虽然各有优点,但成本高、消耗量大或原料来源困难,甚至有的还造成新的污染。化学还原法适用废水流量不大,铬浓度低(<50m g /L ),铬和处理废水不再回用的情况。化学还原处理是先用酸将废水的pH 值调节到适度,再用化学还原剂,如二氧化硫、亚硫酸钠、偏亚硫酸氢盐、连二亚硫酸盐或硫酸亚铁等,将六价铬转化成三价铬,接着又用氢氧化物沉淀予以去除[6]
。本研究发现,以生产钛白的副产物绿矾作为还原剂,对含铬废水用化学还原法处理效果较理想。另外,使用生产钛白的副产物绿矾处理含铬废水,原材料来源丰富、操作费用低、无新的污染,同时还可以回收C r 2O 3。因此,该工艺具有较好的社会经济效率,有一定的推广应用价值。
1 试 验
1.1 主要仪器及试剂
7230G 型分光光度计;P H S -3C 型酸度计;HY -2型调速多用搅拌器。
浓硫酸(分析纯);石灰乳(由工业生石灰现用
现配,质量分数控制在8%~10%左右);绿矾(工业品);含铬废水(C r 6+
含量35~47m g /L ,pH 值5~9)。1.2 方 法
含铬废水处理的工艺流程见图1
。
图1 含铬废水处理工艺流程
试验时移取150mL 含铬废水置于250m L 烧杯中,用1mo l /L H 2SO 4调节废水的p H 值到所需的范围,再加入一定量的钛白副产物绿矾作为还原剂,室温下快速搅拌(转速120r /m in )一定时间,将废水中的六价铬还原成三价铬,然后加入适量的质量分数为8%~10%石灰乳,控制pH 值到所需的范围,并继续搅拌(转速60~80r /m i n )一定时间进行中和沉淀反应,过滤,采用P H S -3C 型酸度计测定滤液的p H 值,用二苯碳酰二肼分光光度法测定
六价铬和总铬[7]
。
2 结果与讨论
2.1 绿矾用量对C r 6+
去除率的影响
固定溶液中C r 6+的浓度为35m g /L ,在还原混合物溶液p H 值为3.5,还原搅拌时间为15m in 的相同条件下,考察了绿矾用量对C r 6+
去除率的影
响,结果见图2。绿矾主要用作还原剂,将溶液中
56
的C r 6+还原成C r 3+。为了保证溶液中的C r 6+
完全被还原成C r 3+
,加入绿矾的量不得低于水样中C r 6+
还原反应的理论需要量。由图2可以看出,铁铬比(Fe 2+
与C r 6+
质量比)越大,C r 6+
的去除率越
高,但当铁铬比大于20以后,C r 6+
的去除率变化不大。因此,试验时矾的用量按铁铬比(质量比)
为20进行投加
。
图2 绿矾用量对Cr 6+
去除率的影响
2.2 氧化还原反应pH 值对Cr 6+
去除率的影响固定溶液中C r 6+
的浓度为35mg /L ,在铁铬比
为20、还原搅拌时间为15m in 的相同条件下,考察了氧化还原反应的pH 值对C r 6+
去除率的影响,结果见图3。从图3可以看出,还原混合物的p H 值
大于4小于5时,C r 6+
去除率不断降低,说明氧化还原反应进行得越来越不彻底,但当p H 值大于等于6时,C r 6+
去除率却反常的高,这时并不是溶液中的C r 6+
发生了氧化还原反应,而是由于还原混
合物的酸度太低,C r 6+
以其他的形式存在于溶液中
[8]
,这说明该氧化还原反应只能在酸性条件下
进行。因此,在确保处理后的水能够达标排放的情况下,为了节约酸的用量及中和沉淀碱的用量,应
尽可能将p H 值控制高一些。本试验将氧化还原反应的p H 值控制在3.5~4.0
。
图3 p H 值对Cr 6+去除率的影响
2.3 氧化还原时间对C r 6+
去除率的影响
固定溶液中C r 6+
的浓度为35mg /L ,在铁铬比为20、还原混合物溶液p H 值为3.5的相同条件
下,考察了还原时间对C r 6+
去除率的影响,结果见表1。由表1可知,在试验条件下,使C r 6+
完全达到排放标准,还原反应时间只需15m in 即可。因此,用生产钛白副产物绿矾处理含铬废水时,其氧
化还原时间控制在15~20m i n 。
表1 不同还原时间Cr 6+的去除率
还原时间/m i n
5
1015202530C r 6+
浓度/(m g L -1) 2.400.920.320.220.160.04C r 6+
去除率/%
93.1
97.4
99.1
99.4
99.5
99.9
2.4 中和反应的pH 值对C r 3+
去除率的影响固定溶液中C r 6+
的浓度为35m g /L ,在铁铬比为20、还原搅拌时间为20m in 的相同条件下,按试验方法先进行C r 6+
的还原试验,然后向还原混合物中加入质量分数为8%~10%石灰乳进行中和
沉淀试验,考察了中和反应的p H 值对C r 3+
去除率的影响,结果见图4。C r (OH )3系两性氢氧化物,在中性、弱碱性或弱酸性溶液中其存在如下两个平衡
[8]
:C r
3+
+3OH
-
C r (OH )3↓
C r (OH )3↓+OH -
C r (OH )-
4
图4 p H 对C r 3+去除率的影响
从图4中可以看出,在p H 值为5.0~6.5的范围内,随着pH 值的增大,C r 3+
去除率逐渐增加,这说明C r 3+
的中和沉淀是主要的;但当pH 值大于
7.0后,随着pH 值的增大,C r 3+
去除率反而逐渐降低,这说明C r 3+的碱性溶解是主要的;当pH 值为6.5左右时,C r 3+去除率达到最大值。因此,p H 值=6.5是C r 3+中和沉淀的最佳pH 值。2.5 中和反应时间对C r 去除率的影响
固定溶液中C r 6+
的浓度为35m g /L ,在已得到的最佳试验条件下,按拟定的方法进行试验,考察了中和反应时间对C r 离子去除率的影响,结果见表2。
用生产钛白的副产物绿矾处理含铬废水
57
表2 不同中和时间下Cr
总
的去除率
中和时间/m i n510152025
ρ(C r
总
)/(m g L-1) 2.650.910.630.630.62
C r6+去除率/%92.497.498.298.298.2 由表2可知,在试验条件下,使C r6+及C r总含量能够完全达标排放,中和反应时间只需10m i n。因此,用生产钛白的副产物绿矾处理含铬废水时,其中和反应时间控制在10~15m in即可。
在上述最佳试验条件下,用生产钛白的副产物绿矾进行多组含铬废水的处理试验,处理后的水样中C r6+浓度均小于0.5m g/L、总铬浓度均小于1.0 m g/L,低于国家排放标准。
3 结 论
(1)用生产钛白的副产物绿矾处理含铬废水的最佳工艺条件为:铁铬比20,氧化还原反应的p H值3.5~4.0,氧化还原时间15~20m i n;中和反应的p H值6.5,中和反应时间10~15m i n。
(2)用生产钛白的副产物绿矾处理含铬废水时,pH值是一个重要工艺条件,无论氧化还原反应还是中和沉淀反应,都需要对pH值进行严格的控制。
(3)中和反应的p H值6.5,中和反应时间10~15m in的工艺条件对含铬废水进行处理,铬的去除率达到97.4%以上,处理后的水样中C r6+含量小于0.50m g/L、总铬含量小于1.0m g/L,且近似中性,符合国家排放标准。
(4)按该工艺方法进行含铬废水的处理,可以回收C r2O3,具有较好的社会经济效率。
[参考文献]
[1] G B8978-1988,污水综合排放标准[S].
[2] 朱耀华.电镀废水治理技术[M].北京:中国环境科
学出版社,1992.
[3] 马洪芳,刘志宝.用铝盐絮凝剂处理含铬废水的研
究[J].材料保护,2003,36(3):53~54.
[4] 夏 清.化学还原法处理含铬废水工艺条件研究
[J].无机盐工业,2003,35(3):37~39.
[5] 夏爱军.还原法处理电镀废水后铬反弹成因分析与
对策[J].环境污染与防治,2003,25(2):107~
108.
[6] 陈新峰,姜献群.氧化还原法处理含铬废水的有关
理论计算[J].南阳师范学院学报,2003,2(3):
43~45.
[7] 污染源统一监测分析方法编写组.污染源统一监测
分析方法[M].北京:技术标准出版社,1983.
[8] 南京大学.无机及分析化学[M].北京:高等教育出
版社,1998.
[编辑:詹小玲]
中国专利
稀土铬复合电镀层的
制备方法及应用
申请号:03135654 公开号:1488783
摘要:电镀层由混合稀土铬基相与硫酸盐和碳酸盐第二相组成。电镀工序由电镀前期、中期、后期3阶段构成,电镀时间均为4h,每个阶段内均进行反相与正相的交替操作;3阶段内正相操作时间分别为30,40,50m i n,反相操作时间除首次为1m i n外,其余均为3m in;稀土铬镀层的厚度为0.3~0.4mm。镀液为:C r O3140~170 g/L,H2SO41.5~2.0g/L,以混合稀土氧化物为主的可溶稀土添加剂2.0~2.5g/L,以硫酸盐和碳酸盐为主的不溶混合稀土盐添加剂3.0~3.5 g/L,其余为水。镀液温度为47~54℃,电流密度为25~30A/d m2。该电镀层作为水轮机的抗磨蚀涂层,具有镀件抗磨蚀性优和硬度高等特点。
成都市龙泉化学品厂
优 供
一、植酸
二、氟碳漆(常温固化型)
地 址:四川省成都市龙泉镇
电 话:(028)85536293
手 机:138********
131********
联系人:彭先生 鲁小姐
开户行:工商行龙泉支行
帐 号:4402234009024819661
税 号:510112202244900
用生产钛白的副产物绿矾处理含铬废水
for m ula and plati ng conditions.The opti m ized p l a ting bat h was
composed of65~95m g/L CuSO
4,15~40g/L N iS O
4
,15~30
g/L N a H
2PO
2
,5~20g/L sod i u m citrate,15~30g/L NH
4
C l,
and12~35m g/L KNO
3.The opti m ized bath p H va l ue was
suggested to be4.5~7.6,wh ile t he te m pera t u re and p lating
ti m e we re sugg est ed to be75~95℃and15~35m i n,respe c-
ti ve l y.T he re s u lting Cu-N i-P coa ti ng had good wea r resist ance and tha t aft e r proper hea t-treat ment wa s ab l e t o furt her increa se
the ox i da tion resistance of t he dia m ond.
K ey w ords:e l ec tro less p lating;Cu-N i-P a lloy coati ng;d i a-
m ond;ox i dati on resist ance;t echno l ogy
Curren t Status and Progress of Study on M i cro-Arc O x i da-tion Techn ology
L I U Y ao-hu i,LI Song(K ey Laborato ry of A utomobil e M a teria ls
o fM i nistry of Educati on,Schoo l o fM a t e rial Science and Engi-
neering,Jili n U niversit y,Changchun130025,China).Caili ao Baohu2005,38(6),36~40(Ch).A review wa s g i ven on the develop m en t o fm icro-arc ox i dati on techno logy since its estab lis-h i ng in1960s,w it h the powe r supply,e l ec tro l y te,and s ubstra te m e t a ls t o be f o cused on.The distributi on rules of t he co m po si-ti ons and phase structures o f t he m ic ro-a rc ox ida tion coati ng s, as w e ll as the i nfl uences o f current densit y,ox ida tion ti m e, vo lt age,electro l y tes,and o t her factors on t he g row t h and p rop-e rties of t he coa tings we re su mm a rized.It w as pointed out t ha t the re still ex ist so m e disadvan t ages in the re lated theo re tical re-search and produc tion cost contro l of the m icro-arc oxidation techno logy,t hough it has a p ro m isi ng applica tion perspec tive.
K ey wo rds:m icro-arc ox i dati on;cera m ic coati ng;surface modi-
fica tion
Curren t S tate and Progre ss i n T echnology and M echan is m for E l ec trodepositi on of C o m posite C oati ngs w ith N anopar-ticu l ates
SUN W ei,ZHANG Q i n-y i,YE W e i-ping,HUANG Shang-yu (Schoo l o fM ateria ls Sc i ence and Eng i neering,W uhan U niversi-ty o f T echno l ogy,W uhan430070,Ch i na).Caili ao Baohu 2005,38(6),41~44(Ch).A rev i ew w as g i ven on t he recen t p rogress and ex isti ng proble m s in t he research of the techno logy and m echanis m for the e lectrop l a ted co m po sit e coa tings inco rpo-ra ted w it h nanoparticula t es.The t hree theo ri e s and six models concerning t he nano m e t e r elec tro-deposition mechanis m w ere h i gh li gh t ed,while the advantag es and disadvan t ages o f various m ode ls we re s umm arized.M oreove r,the directi ons i n t he depo-sition m echanis m and m athem atic m ode lw ere sugge sted.It was po i nted out that nanome ter composite coa ting s had high ha rdness and excell ent wear and corro sion resist ance t han conven tiona l composit e coa tings.
K ey wo rds:composite elec trodepositing;co m po sit e coa ti ng;
nanome ter pa rticle;deposition me chan is m
H ot Corrosion B ehavior of FeCrA l W/C C o m posite Coa ti ng Prep ared b y H igh Ve loc ity Arc Sprayi n g
HU Jun-zhi,C HEN X ue-rong,M A Shi-ning,D I NG H ua-dong (N ati onal K ey Labo ra tory of Equ i p m ent R e m anufac t uring,A-cade m y o fA r mo red Fo rces Eng ineering,Be ijing100072).Cail-iao Baohu2005,38(6),45~47(Ch).W it h a v i ew t o the shutdow n o f powe r plan t ow ing to the c rack o f the bo il e r t ube by ho t corro sion and e rosion,t he hot co rro sion behav iors o f Fe-Cr A l W/C co m po site coa ting produced by high ve l oc ity arc spra-y ing and G20st ee l used as t he w a t e r t ube w a ll m ate ri a l o f the powe r st a tion bo il e r we re inve sti ga ted.T he ho t co rrosionm echa-n is m o f the F eC r A l W/C composit e coati ng w as exp l o red as we l.l The results i ndicated t hat F eCr A l W/C composite coa ting had ex-ce ll ent ho t corro sion re sistance.N a m ely,the w eight ga i n of the G20st ee l a fter80h corrosi on testw as2.1ti m es o f t ha t of the FeC r A l W/C coating under the sa m e test conditi on.The Fe-Cr A l W/C co m po sit e coa ti ng w as liable to hot corro sion in a m o l-ten sa lt hea t ed t o650℃.The co rrosion of t he FeC r A l W/C composit e coa ting w as attri buted t o t he co m bi ned ac tion of diffu-si on and che m ica l and e l ec trochem ica l reacti on o f Fe,w he re the ox i dati on and depo sition o f F e
2
O
3
on the interface of the m o lten salt/gas played a predo m i nant role.
K ey wo rds:high ve locit y a rc s pray ing;co m po sit e coa ting;bo il-er t ube;ho t co rrosion
Fa ilure M on itor i ng of T i-Based Ir O
2
-T a
2
O
5
O x i de Anode and Exp loration of th e Fail ure M echan is m
ZHAO Y a-ling a,LONG X iu-hui b,C HU L i-y ing b(a.Co ll ege of B asic Science;b.Co ll ege o f M ateria ls Science and Eng ineer-i ng,Changchun U niversit y o f T echno logy,Changchun130012, China).Caili ao Baohu2005,38(6),48~51(Ch).T i-based Ir O
2
-T a
2
O
5
ox ide anode w as prepa red by the r m al decom posi-tion.T he fail u re m echan is m o f t he ox i de anode w as stud i ed. T hus t he varia tions in the mo rpho l ogy and e l ec trochem ica l prop-er ties o f the ox i de anode subjec t to acce lerated e l ec tro lysis i n a-queous sulfuric acid w ere exa m i ned by m eans of scanning elec-tron m icro scopy(SE M),cy clic vo lt amm etry(CV),and elec-trochem ica l i mpedance spectroscopy(EIS).The results show ed t ha t the fail u re of t he oxide anode w as no t attri buted t o t he elec-troca t a l y tic deac tiva tion of t he ox i de co ating itself bu t t o t he large a rea de l am ina tion o f t he oxide coa ting caused by t he co rro-sion passivation of t he substra t e m eta lwh ich made t he substrate unab l e to ac t as t he e l ec tric conducti ve s upporter.
K ey w ords:ox ide anode;acce l e ra t ed e lectro l ysis;proce ssm oni-t o ri ng;electrocata l y tic ac tivit y;fail ure m echanis m
C orrosion Behavior of An tiru st LF21M A lu m i num A lloy i n NaC l Salt Spray
HUANG W ei1,L I D i1,GUO Bao-lan1,HUANG F eng-chun2 (1.Schoo l o fM a t e rials Sc i ence and Enginee ri ng,Be iji ng U ni-versity of A eronautics and A stronau tics,Be ijing100083;2.In-stit u t e of A pplied Chem istry,Shanx i U niversit y,Ta i yuan 030006,China).Ca ili ao Baohu2005,38(6),52~54(Ch). T he co rro sion behav ior o f LF21M all oy in a neautral sa lt spray of N aC l w as i nvestigated.Thus the corrosi on behav i o r o f t he LF21M a ll oy w as analyzed m aking use of neu tral salt spray t e st i n co m bina tion w ith scanning e l ec tron m ic roscopy(SE M),en-ergy dispe rsive X-ray spectro m ete r(EDS),X-ray d iffrac tion (X RD),and po tentiodyna m ic po l a rizati on curve m easure m en.t R esults s howed t ha t the LF21M a l u m inu m all oy w as liab l e to pitting co rrosion in hu m i d env iron m ent conta i ning chloride i on. How eve r,a t hin and condense alu m inu m ox i de fil m w as for m ed on the corroded s urface,wh ich w as ben ifica l to increa sing t he corrosi on resist ance o f t he LF21M alu m inu m a lloy.
K ey wo rds:co rrosion behav i o r;pro t ec tion;an tirust LF21M a l u-m inu m a lloy
Ch ro m i um-Con tai n i ngW aste w ater T reat m en t by C opp eras B yproduc t i n T itan i um D ioxi d e Product i on
YANG M ing-ping,FU Yong-jian,L I G uo-bin(School of Che m istry and Chem ical Eng i neering,H unan Unive rsity o f Sci-ence and T echno l ogy,X iang tan411201,China).Cailiao B ao-hu2005,38(6),55~57(Ch).I t is i m pe ra ti ve t o develop no-ve l e ffi c ien t techno l ogy fo r t he treat m ent of C r-containing w astewa ter,be cause various avail ab l e me t hods f o r the treat ment o f C r-con t a i n i ng w ast ew ater have many li m it a tions in prac tice. T hus copperas as t he byproduc t i n t he production o f titan i u m di-oxide(tit aniu m whit e)w as used as a reducing agent to trea t C r -containing w ast ew ater.T he pro ce ss conditions w ere st udied w it h re s pect t o oxida tion-reduc tion,neu tra lization-prec i pitati on, separati on,and so on.The opti m um techno l og ical conditi ons we re s uggested as Fe/C r rati o20,p H va l ue o f oxidation-reduc-tion reac ti on3.5~4.0,oxidation-reducti on ti m e15~20m in, p H va l ue o f neutra liza tion reac tion6.5,and neu tra lization ti m e 10~15m i n.M o reover,t he chro m i u m i n t he w aste w ate r con tai-ning about35mg/L w as re m oved at a ra te over97.4%,and t he C r6+content and t o tal chrom iu m w ere l ess t han0.50m g/L and less than1.0m g/L,respecti ve l y,a fter trea ting u sing the op ti-m ized techno log ica l cond itions.The trea t ed wa ter w as qua lified t o the nati ona l discharge st andard.
K ey wo rds:wa stewa ter trea t m ent;w aste w a t e r con t a i n i ng chrom i-u m;copperas;ox i da tion-reduc tion reac ti on;neu tra liza tion-pre-cipita tion reac tion
T echnology and E qu i p m en t for Cathod e E lectrophoresis Coat i ng of Car Fra m es
ZOU Y ong-feng(N o.2P ro ject P l ann i ng and Resea rch Instit ute, M inistry o f M achine ry Industry,H angzhou310022,Ch i na). Cailiao Baohu2005,38(6),58~60(Ch).A new t ype produc-ti on line w it h se lf-prope lled cranes for t he cathode e lectropho re-sis coati ng of car fra m e w as used as an exa m ple t o i n troduce the techno logy processes and conditions concerning the car fra m es w it h scale and w ithout rust-remova l prio r t o t he coati ng.A n u l-trasonic pick li ng techno l ogy w as pre sen t ed fo r remov i ng t he rust and sca l e o f t he car frame.T he principle fo r t he equ i p m ent se-lecti on and t he a rrangement of t he equip m en ts w ere d iscussed, w hil e t he prob l em s in the de sign of t he p roduction line w ere pro-posed as we l.l
K ey w ords:ca t hode e lectropho resis co ating;ca r fra m e;co ating p roduction li ne
Corrosi on Preven ti on of S teel G ate for T i de Lock by Spra-y i ng Polyurea E lasto m er
ZHU X i-chang,G E Y an,ZHU Y a-x ian(N anji ng Hydrau lic Re-search Institute,N anji ng210029,China).Cailiao Baohu 2005,38(4),61~63(Ch).A brie f i ntroducti on w as g i ven on po l yurea e last om er spray i ng as a ne w co rrosion protecti on m eth-od f o r the stee l ga t e of tide l o ck.T he t e chn ica l characteristics and advantages of t he pro cessw ere s umm arized,and accele rated co rrosion test and fie l d t e st we re ca rri ed ou t to verify its vali dit y in prac tice.It w as found t ha t t he sprayed polyurea e last om er cou l d be used to e fficien tl y prevent t he steel ga te from corro-si on,and the t echno l ogy cou l d have enor m ous long-t e r m eco-no m ic bene fi.t
K ey w ord:co rrosion preventi on;st ee l g ate;polyurea e l a stome r M eas u re to Preven t D i m C oati ng Dur i ng H ot-D i p Ga l van i-zing of Q345S tru ctural S teel
W ANG Y an-ning1,L I ANG Zhong-hua2,M I AO L i-x ian1,SH I X ian-hai3(1.T i anji n G ongda G a l v anizing Equip m en t Co.L t d, T ianjin300132;2.H enan Z hu m adian R esearch Instit u t e o fA g-ricu ltura lM echaniza tion,Zhu m ad i an463000;3.H enan Zhu-m ad ian Ho t-D i p G a l vanizing o f T ube and T o w er,Zhu m adian 463000,Ch i na).Cailiao B aohu2005,38(6),64~66(Ch). During the hot-dip g alvan izi ng o f Q345h i gh streng t h low a lloy (H SLA)struc t ural steel,the unde sired silicon contained i n the st ee l l eads t o t he for m a tion of di m and ove r-t hick coa ti ng and increase s t he p roducti on co st as we l.l The reason lies i n t hat the st ee l of a Si content over0.25%s ubject t o ho t-dip g alvan izing at460℃is liable t o an intense Z n and F e reac tion,which m akes t he depo sit d i m,over-thick,and of a l ow adhe sion streng th to t he substrate.Thus it wa s suggested t o adopt t he fo l-low i ng measures so as to get rid of the d i m and ove r-t hick f o r-m ati on of coa ting on ho t-dip ga l vanized Q345stee l a t430~450℃.N a m e l y,t o adjust t he lifting rate of t he pa rts ou t o f the ga l-vanizing bath using frequency-converting technique(set as2~30m/m in),to add a s m all a m ount o f zinc-ba sed a ll oy contai-ning B i and Sn,to control the iron i on content be lo w1g/L u-
sing ga l vanizi ng additi ve s and iron re m ova l equip m en t,and t o a-
void ove rpickling and repetitive pick ling all he l ped to evade t he
di m and over-t h ick coati ng fo r m a tion on t he ho t-dip ga lvanized Q345stee.l
K ey wo rds:ho t-di p galvan izi ng;Q345HSLA structura l st ee l;
di m coa ting;con tro lm easure
D eterm i na ti on of Several M eta l
E l em en ts i n E lectrol yt i c C ol oring An od i z i ng Coat i ng on A l um inum A lloy by G raph-ite Furnace A to m i c Ab sorpt i on Spec tro m etry
YANG X iao-y an a,YAN L i u-s hui a,DU N an b,W EN Zhen-dong a,D I NG Yuan a(a.D epa rt m en t o fEnviron m en t and Che m i-ca l Eng i neering;b.D epart ment of M a t e rial Sc i ence and Eng i-nee ri ng,N anchang Institute of A e ronautica l T echno l ogy,N an-chang330034,Ch i na).Ca iliao Bao hu2005,38(6),67~70 (Ch).Standard addition calibration techni que was used i n t he g raphit e furnace a t om ic absorp tion s pec trome tric(GFAA S)a-na l y sis o f copper,nicke l,and ti n i n the e l ec tro l y tic co l o ri ng an-odizi ng coati ng on a l um inu m so as t o e ffec tively reduce interfer-ence o f t he coex isten t e le m ents i n t he samp l e so l u tion and i n-crease the measure m ent accuracy.T hus the linea r range w as pre li m ina rily de ter m ined usi ng standa rd cu rve me t hod,t hen t he opti m al dil uti on ti m e s fo r t he solutions t o be test ed and a se ries o fw ork i ng so l u tionsw ere de t e r m ined,which m ade it possible to accord i ng ly de ter m ine the linea r ranges w it h highe r correla tion coeffic i ents for coppe r,nicke l and tin(0~0.6m g/L Cu,0~0.8mg/L N i,and0~0.7m g/L Sn,respecti ve l y,w ith respect t o standa rd addition ca libra ting curves).It w as f ound t ha t t he i ncrease i n t he nicke l conten t of t he Cu-N i-Sn te rna ry syste m led to dec rease in the li near corre lati on coeffic i ents of coppe r and tin in t he standard addition ca libra ting curve s.
K ey w ords:dete r m i na tion;graphite furnace ato m ic absorp tion
spectro m e try(G FAAS);standard additi on m e t hod;anodiza-
tion;e l ec tro l y tic co l o ri ng
D eterm i na ti on of Sod i um B en zene s u lf i nate i n H igh Su lfur N ick el
E lec trop lati ng Ba th
ZH E NG Y i ng,GAO C an-zhu,LIU Chun-hua(Schoo l o f Env i-ron menta l Sc i ence and Eng i neering,Shandong Un i ve rsit y,Ji nan 250100,China).Ca ili ao Baohu2005,38(6),71~72(Ch). W it h a v ie w t o t he i m po rtance o f the accura t e deter m i nati on of additive concentra tion i n gui d i ng t he efficient troub l e s hoo ting and coati ng qua lit y i m prov i ng for h i gh sulfur n i ckel e l ec tropla-ting p rocess,t he concentration of t he sod i u m benzenes u lfi nate additive contained in a high sulf ur n i ckel electroplati ng ba t h w as de ter m i ned using u ltravio l e t spec tropho t ome try.Thus t he m e t hod t o de ter m ine t he sodiu m benzene s u lfi nate in the h i gh su lf u r nicke l elec troplati ng ba t h wa s est ablished,and the i n fluence s of p H va l ue and i norgan i c sa lt on t he absorbance o f t he sod i u m benzene s u lfi nate we re studied.Itw as found t ha t the me t hod es-tab lished had the advan t ages o f rap i d and accura t e m easurement and cou l d be app lied t o t he fie l d analysis of t he s od i u m benzene-su lfina te in industrial high s u lfur nicke l e l ec tropla ti ng baths.
K ey w ords:de ter m ination;nicke l e l ec tropla ti ng;h i gh su lf u r
nicke l;additive;sod i u m benzenesulfi na t e
Seaover Ed itor i a l C o mm itt ee:K.V.Frolov,V.T.Troshchenko,L.A.Sosnovski y,
Yu.N.Drozdov,T.Bell,H anshan D ong,Lee H ongK ee
Journal ofM ateria ls P rotecti on V o.l38.N o.6,June2005 Published by M ateria ls P rotec tion Pub lishing House Edited by M a t e rials P ro t e ction Edito ri a l D epart ment
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