PLEASE DO NOT REMOVE FROM LIBRARY a R I 9 0 2 4 Q ^— 0 s * Bureau of Mines Report of Investigations/1986 Solubility of Anhydrous AICI3 in TiCI4 and VCI4 By Dennis A. Hansen and Davis E. Traut UNITED STATES DEPARTMENT OF THE INTERIOR tteport of investigations 9 0 2 4 Solubility of Anhydrous AICI3 in TiCI4 and VCI4 By Dennis A. Hansen and Davis E. Traut UNITED STATES DEPARTMENT OF THE INTERIOR Donald Paul Hodel, Secretary BUREAU OF MINES Robert C. Horton, Director Library of Congress Cataloging in Publication Data: Hansen, Dennis A Solubility of anhydrous3 in TiC^AICI and VCI4. (Report of investigations / Bureau of Mines ; 9024) Bibliography:8 .p. Supt. of Docs, no.: I 28.23: 9024. 1. Aluminum chloride—Solubility. 2. Titanium tetrachloride. 3. Vanadium tetrachloride. I. Traut, D, E. (Davis E.). II. Title. III. Series: Report of investigations (United States. Bureau of Mines) ; 9024. TN23.U43 [TP245.A4] 622s [669’.7322] 86-600041 CONTENTS A b s t r a c t .................................... ................................................... 1 Introduction........................................................................ 2 M a t e r i a l......... s ............................................................... - ........... 3 E q u i p m e n.................... t .................................................................. 4 Experimental p r o c e d u r e ....................................................................... 5 Results and d i s c u s s i o n . ..........................................................6 C o n c l u s i o n s ..................................................................................... 8 R e f e r e n c e s.................................. ................................................... 8 ILLUSTRATIONS 1. Autoclave a s s e m b l y ....................................................................... 4 2. Top half of a u t o c l a v e ................................................... ................ 4 3. Solubility of AICI3 in Ti C l 4................................................ ......... 6 4. Solubility of AICI3 in TiCl4—a comparison of results................... 6 5. Solubility of A1C13 in VC 1 4..................... ..................................... 6 6. Solubility of AICI3 in Ti C l 4- V C l 4 s y s t........................................... e m 6 7. Effect of V C4 I concentration on 3AICI solubility in TiCl4- V C l 4 s y s t....... e m 7 TABLES 1. Spectrographic impurity a n a l y s i s ...................................................... 3 2. Equilibrium time for solubility 3of in AICI T i C l 4 and V C 1 4 at 75° C......... 5 3. Summary of solubility data for the4- A l CTiCl l 3-V C l 4 s y s t..................... e m 7 UNIT OF MEASURE ABBREVIATIONS USED IN THIS REPORT °c degree Celsius ym micrometer h hour psi pound per square inch K kelvin rpm revolution per minute L liter wt pet weight percent mL m i lliliter SOLUBILITY OF ANHYDROUS AICI3 IN' TiCI4 AND VCl4 By Dennis A. Hansen1 and Davis E. Traut2 ABSTRACT The solubility of anhydrous aluminum chloride in solutions of titanium tetrachloride and vanadium tetrachloride was determined as part of a re­ search project by the Bureau of Mines to make a homogeneous alloy sponge of titanium, vanadium, and aluminum. Solubility curves were established using an autoclave at 75°, 100°, 125°, and 150° C. The solubility of AICI 3 in T i C l 4 is 0.2 wt pet at 75° C; it increases to 18.3 wt pet at 150° C. The data concur with data from earlier researchers of this bi­ nary system for 75° to 125° C. For4-AICI the3 VCIbinary system the solubility of AICI3 is 0.1 wt pet at 75° C, increasing to 1.6 wt pet at 150° C. For the TiCl4- A l C l 3- V C l 4 ternary system the solubility3 of AICI decreases from the values found with a pure4- A l C lTiCl3 system to the lower values found with a pure4-AICI VCI3 system at the respective temperatures. 1 Chemical engineer. Supervisory chemical engineer. Albany Research Center, Bureau of Mines, Albany, OR. 2 INTRODUCTION The Bureau of Mines is conductingavailable were limited to the solubility studies on several approaches toof makeA I C I3 in TiCl4 . high-quality titanium alloy powder. Sav­To determine the solubility of3 inAICI ings in cost and reduction of wasteTi Cmay l 4 , Eingorn (4^ used a thermal analy­ be realized in the production of titaniumsis method and investigated the system alloy products by the use of powderfrom met­ -24° to 120° C. Through a lateral allurgy techniques to produce high qual­extension in a glass vessel, just enough ity, near-net-shape parts. Several Tmeth­1C 14 was poured in to cover the thermom­ ods for producing spherical, high-purityeter bulb. The melting temperature of titanium alloy powder are being investi­the pure solvent was measured. Then a gated throughout the industry, butsmall only amount of AICI3 was added and the one method, the Plasma Rotating electrodetemperature of crystallization was again Process (PREP), has been proven to dpro­ etermined to estab l i s h a cooling curve,, duce a powder of high enough quality forMorozov (_5) used a saturation method use in aircraft manufacture_).3 (J Pro­ from 18° to 80° C and a thermal analysis duction of powder by the PREP processmethod is from 93° to 193° C. In both meth­ expensive because of the necessity ofods us­ a sealed vessel was used. For the ing electrodes accurately machined andsaturation method the chlorides were ground from billets forged from double-sealed in one arm of a two-armed glass or trlple-arc-melted alloy ingots.apparatus, Di­ and kept at the desired tem­ rect production of spherical alloyperature powder for 20 to 40 h. Then part of from titanium alloy sponge could elimi­the transparent supernatent was poured nate most of these costly meltinginto steps the unused arm. This arm was then and result In significant cost savings.cut off and the solution analyzed* For In the approach used by the Bureau the(2^) thermal analysis method a known to make alloy sponge, the chloridesweight of of each of the chlorides was titanium (Ti), vanadium (V), and aluminum placed in a seated apparatus, and the (Al) are simultaneously reduced by magne­apparatus was subjected to heating and sium (Mg) via a Kroll-type reaction.cooling. A The resulting temperature was homogeneous (as to Ti, Al, and V distri­measured by a pyrometer. Morozov's re­ bution) powder is considered essentialsults are currently used as a reference for final titanium alloy part integrity(6). (3). (Thus, both a homogeneous titaniumDruzhinina (_7) used a saturation method alloy sponge and a homogeneous metalfrom 55° to 150° C, very similar to that chloride feed are required to make usedthe by Morozov, As with Morozov, the powder.) At room temperature, titaniumclear supernatent was decanted from one tetrachloride (TiCl4) and vanadium tetra­test tube leg to another in a sealed sys­ chloride (VC14) are liquids, while alumi­tem. Mixing was done periodically by num chloride (AICI3) is a solid. A dis­shaking the test tube apparatus. From 4 persion of minute, solid3 particlesAICI to6 h was required to reach equilibrium in the liquid TiCl4”VC l 4 phase would notsaturation. Druzhinina found that the be desirable, as this would adverselythermal im­ analysis method for determining pact homogeneity (2^, p. 20). Therefore,solubility of this system was not satis­ the solubility relationship 3 ofin AICIa factory owing to the supersaturation of T i C l 4- V C l 4 solution was required to AICIprop­3 in TiCl4 . erly prepare feed solutions for theEhrl Kroll i c h (8) used a saturation method work, but this relationship was notfrom found 25° to 125° C in which the chlorides in the literature. The solubility weredata combined in a stirred container for an unspecified time to reach equilibrium. ■^Underlined numbers in parentheses Thenre­ a sample was taken. Ehrlich com­ fer to items in the list of referencesmented at that the data obtained by Morozov the end of this report. could not be confirmed and that the 3 solubility values of 3AICI in H C I 4 d e ­ researchers' methods and a duplication of termined by Morozov were about 10their times results in the 4-TiCl A l C l 3 system higher than his own solubility values.would confirm the Bureau's experimental Ruban (9) also used a saturation methodmethod and procedures as applied to not from 70° to 127° C, but with an unsealedonly the TiCl4- A l C l 3 system but also to reaction vessel. The equilibrium timethe T i C l4- A l C l 3- V C l 4 system. for each temperature was determined;Morozov it was the only researcher who ranged from 38 to 40 h at 70° C downused to the thermal analysis method to de­ 15 to 20 h at 127° C. Ruban expressedtermine solubility O ) . The data ob­ concern that the6-h equilibrium time tained in that study are not consistent used by Druzhinina was too short andwith thus four other studies. Ruban suggested produced low AICI3 solubility. that the thermal analysis method may not Martynov (10) used a saturation methodallow the system to reach equilibrium from -20° to 50° C in a stirred quartzsaturation owing to insufficient time vessel (11). Martynov compared the atdata a specific temperature. In addition, of Ehrlich, Druzhinina, Ruban, and Mor­the method would require the determina­ ozov with his own and found the datation of of solution composition by the input Morozov to be significantly differentof known weights and volumes of the mate­ from data from all other investigators.rials rather than actual analysis. Both The emphasis of this study was thethe sol­ possible hydrolysis of the materials ubility of AICI3 in a T i C l 4- V C l 4 system.