Step 1: Understand the context of the problem
The problem seems to be related to the recycling or recovery of gold, denoted as 58 in the context、This could refer to a specific process, alloy, or percentage related to gold recycling.

2: Identify what 58 could represent in gold recycling
In gold recycling, especially concerning gold alloys, 58 might refer to a specific karat rating or purity of gold、Gold purity is often measured in karats, with 24karat gold being 99.9% pure、However, without a specific context, it's hard to determine if 58 refers to a karat rating, a percentage, or another measure.

3: Consider common gold purity measurements
24K gold is 99.9% pure.
22K gold is approximately 91.6% pure.
18K gold is about 75% pure.
14K gold is around 58.3% pure.

4: Analyze 58 in the context of gold purity
Given that 58 could potentially refer to a percentage or a part of a measurement system for gold purity, it's close to the 58.3% purity mark, which is associated with 14karat gold.

5: Conclusion based on given information
If 58 refers to a gold purity or alloy rating, it's likely related to 14karat gold, which is 58.3% pure gold、This is a common alloy used in jewelry and other applications.

The final answer is: $\boxed{14}$