sold at scrap 300 lbs of 90 % silver is equal to 270 lbs of 999 pure silver the silver purity level of "spot silver price" -- in a normal 16 oz type lb (pound) there are 14.583 troy oz --the troy oz is bigger than the standard oz. ( metal like gold and silver are dealt in troy oz's)-- so take 270 lbs x 14.583 (troy oz per pound) to give you the number of "troy oz you have --- times the result by the current "silver spot price" -- to find out its actual spot silver value -- thats what its worth -- but to sell it-- you often have to "sell it at a discount % wize" some what less than spot .