The Bureau of Mines investigated the recovery of vanadium, uranium, and phosphorus from low-grade phosphorite ores and concentrate by leaching with h2so4. Samples containing 0.12 to 0.23 pct v2o5, 0.009 to 0.012 pct u3o8, and 18 to 30 pct p2o5 were treated by batch- agitation leaching, roasting followed by acid leaching, salt- roasting followed by acid leaching, and leaching under pressure. Maximum recoveries using leaching alone ranged from 78 to 98 pct of the v2o5 and 74 to 88 pct of the u3o8. Leaching under pressure resulted in extractions of 88 to 95 pct of the v2o5 and 84 to 89 pct of the u3o8. Leaching following roasting--with or without nacl-- produced extractions of 97 to 99 pct of the v2o5 and 86 to 91 pct of the u3o8. Depending on the technique(s) employed, phosphate extractions ranged from 89 to 99 pct. Solvent extraction laboratory tests were conducted to selectively recover vanadium and uranium values from acid leach solutions. An average of 95 pct of the u3o8 was recovered using di(2-ethylhexyl)phosphoric acid, plus trioctylphosphinic oxide. Essentially all of the v2o5 was recovered with octylphenyl acid phosphate plus isodecanol. The phosphate remained in the raffinate.