Double slag method: blowing process needs to pour or scraped out parts of slag (approximately 1 / 2-2 / 3), high oxygen scavenger, and then re-added slag slagging. Advantages: remove phosphorus, high sulfur effect; can eliminate a lot of splash caused; reduce erosion of the lining, Shandong efficient oxygen scavenger, to reduce lime consumption. Its dephosphorization rate of 92% to 95%, Jiangsu efficient deoxidizer, desulfurization rate of about 50%. Conditions: molten silicon or greater than 1.0% phosphorus greater than 0.5%; n feed phosphorus content of less than 0.5%, but requires the production of high quality steel phosphorus; blowing, high-carbon steel in the furnace and the need to add a lot easily oxidizable alloy elements. Disadvantages: prolonged blowing of time, increasing heat loss, reduce the yield of metal is not conducive to the process of automatic control. Key to: determine the appropriate time to put the slag. Melting period: melting of steel mainly for the purposes of open-hearth and electric furnace steelmaking. EAF charge from the energization start to melt all clear so far from open hearth to the charge against the hot metal finish all of finish far have said melting period. Melting of the charge as soon as the task is melted and heated, and make good melting of the slag.