Document 4aRdZNJVkX6ODxNGm9wg6K6BR

E. I. DU PONT DE NEMOURS & COMPANY KREBS PIGMENTS DEPARTMENT 256 VANDERPOOL STREET NEWARK, NEW JERSEY Serial No. KS-44-3? Copy No. / y t T' jfc, ^; Y Period Covered: NEWARK PLANT PIGMENT COLOR RESEARCH REPORT Final sport ZXHC YELLOW* X-53<?-D CMTEIKJGB WASHISG COSOmoHS - GCAL YIELD. FEBRUARY 15 to MAX 10, 1944* FILE: DATE: 212 6-7-44 IfjB3a$ N37969 Serial Be. S844~if Copy Be* / Copy tot #1 - Humorleal File , 3 - Research Qttioo (212) 13 -: FLitetary*F*il*e s(212) i * Industrial SngiaeeriBg Dept. (Bewarfe) SSWARX PLMT rtmmt c o l o r r e s e a r c h r b p om Final Report Title* ZIBC TELLOW, X-539-D cmsmmm wmm c o h d it io b s - g o a l f ie l d Period Covered* F1BRUAHF 1? to MAX 10, 1944. SUBMITTED * APPROVED B7 F. 0HA1UPSK1 ^ lAvntf /tyy DAT! SUBMITTED* 5--12-44 DATS ISSUED* , ,, -M DUP050149947 In With preSt given t , the goal yield for x being Sine follow by flooding and separating in a tw 4a%a|wi<it* the yields to be A study has also been made of the 0f *uah conditions as px a*nf teuperatlao of stieslag* la addition, preliminary on a method of countercurrent washing by which Is greatly curtailed and loss ia yield railiced. , Average yield of a charge of X-539-0# mrns; ing the equivalent of 1877 lbs. sine oxide soft washed by a laboratory' Oqafcwf tyi am||{|b lag. filtering funnels, which duplioatea tbs conditions of eantrifugo bias. was 4247 lbs. ona the *a00 lIes* basis and 423? lbs* anhydrous basis* '$bia is comparabla to 4350 lbs* obtained; eWbiioVntt the pigment ms mashed oa tbs funnel,equivalent to press washing (See XR-44-15)* fins of stirring tho Zinc follow slurry with the wash varied from 3 bears to 30 minutes without notiooablo change in offte lemey of lag, as indicated by tbs chloride content of the pigment. Holds wsro also a Higher temperature ef wash water (above 80 7.) did not result in lower chloride content as might be expected* fields suffered a pronounced reduction especially in the range from 110 to 150F. dm to inereasod solubility ef ZnO and CrO*. 'Previous experienoa baft indicated that with water colder thah 80F. , removal ef chlorides it ftlowod down perceptibly* She amber of wash waters waa tied from three now used to meet the prosat specification of 0. !1 to o total of flvo mters* Chloride* were reduced from ~ obtained with three waters to 0.,00215 iwith one additional flooding* A leas in yieM amei tag to roughly If (actually 1*135) occurred* He further reduction In pereentago of chlorides rcsultod from a fifth pass but tho yield lowered as by the previous washing. She pi of the wash watsr was found to be an important factor in influencing losses duo to solubility ef ZnO and CrQj. ZnO losses increase slightly through tho range of 7*0 to 8*35 ml become considerably higher at 6.0? and below* Irti losses ore at a minimum in tho raago of 6.65 to 6.05# ptisan yields wars obtained between 8*65 and 8*35 which is tho range normally resulting when no adjust ment ef the |B of the wash watars is made. filtrate losses and mage of water wore materially reduced by a system of eounterourrent washing studied in cooperation with I.E.D. A considerable proportion of the yield loss which occurs with the centrifuge type of washing was prevented by the recircula tion of the effluent from the second and third passes for use in DUP050149948 tha first sat second washings respectively. Shia involves dilution of tha original strike slurry which weald Bake use ef the ftitrate so a by-product Bora uoeoononioal. Beeovary is only slightly loss if this stop is oadtted ai only tha third pass effluent recirculated. Chloride content of tha finished product# last at tha Halt of 0.0511. the following ara |1U figures for tha equivalent of plant charges of 107? lb*. of 2n0 washed by diffareat laeihodst- Centrifuge type washing With fresh water - 4265 Its. thirl pass afflnsnt recirculated - 4321 * (First pass uuanddiiluted) Second and third paasss effluents recirculated------ ---- --- ------- --4Mt.. Press type washing - 4 Hotebooke 908 and 1044. fha effect of throa pastas through tha centrifuge which arc required In tha plant for satisfactory washing, was duplicated in the laboratory by dilution of the pigaent slurry to about one pound solids por gallon, stirring this susponslon and then filter ing on a funnel, The wot cake was then repulped at the same concen tration, filtered and repulped for the third washing. Charge was one tooth of K-1948 on a graw basis. DU P050149949 DUP050149950