摘要 |
<p>Two low cost processes for removing boron, phosphorus, carbon and titanium during the process of converting metallurgical grade silicon to electronic grade silicon are described. A first process removes boron and titanium by using one or more high temperature solids removal devices for the removal of solid titanium diboride from a halosilane reactor effluent stream where the high temperature is greater than about 200° C. A second process removes carbon as methane and phosphorus as phosphine by means of a membrane separator which processes all or part of a hydrogen recycle stream to recover hydrogen while rejecting methane and phosphine.</p> |