JP-2025514435-A5 -

Dates

Publication Date

20260511

Application Date

20230428

Description

In a preferred embodiment, the reducing gas also contains water. The water is added at a predetermined time after the start of step B. This predetermined time is preferably before the temperature of step B reaches 650 degrees Celsius. In a more preferred embodiment, the temperature is selected from a list consisting of 500 degrees Celsius, 550 degrees Celsius, 600 degrees Celsius, and 650 degrees Celsius. In another preferred embodiment, the predetermined time occurs within a range selected from a list consisting of 500 degrees Celsius to 550 degrees Celsius, 550 degrees Celsius to 600 degrees Celsius, 600 degrees Celsius to 650 degrees Celsius, 500 degrees Celsius to 600 degrees Celsius, and 500 degrees Celsius to 650 degrees Celsius. In a very preferred embodiment, the water-to-hydrogen ratio ( H₂O : H₂ ) on a molar basis is between 1:20 and 5:1 . The water-to-hydrogen ratio is preferably between 1:2 and 2:5. In a highly preferred form, the water-to-hydrogen ratio is between 5:1 and 1:1. After cooling of the reduced substance (3), an optional step D, which is an acid leaching step, is performed. It is expected that sulfuric acid with a pH of approximately 3 will be used in this step. (Best Mode for Carrying Out the Invention) In further modifications of this method, step A is still optional (but preferred), but the reducing gas (2) contains H₂O to H₂ in a molar ratio of 1:2 to 2:5, i.e., 2 molar hydrogen to 1 molar water to 5 molar hydrogen to 2 molar water. As a result, the reducing effect of the reducing gas (2) changes. It has been found that the required properties are obtained when the water-to-hydrogen ratio is in the range of 1:20 to 5:1 .