Horsehead's future earnings will depend in part on the company's ability to reduce the cost of producing zinc (the company having already made considerable progress in this regard) and it will depend to a large extent on the future price of zinc. The future price of zinc is, of course, unpredictable. Thus, Horsehead's future earnings are unpredictable.
as I see it, Horsehead doen't produce Zinc - they buy zinc scrap in all forms and then using energy convert it into useable product, oxide - whatever. Unfortunately, companies like this usually lose sight of absolute earnings and instead produce lots of reasons why they are doing great such as premium over metal and such. This business is run for the insiders not the shareholders but the stock may do well as a hedge against the federal printing presses.
I completely agree with you that the price of Zinc will dictate their earnings. Further, commodities are a penny business and it's important to keep good customers on your books who pay and will continue to pay for product. Areas such as customer service are important. Have any of you tried to call their 800 number and gotten an recorded message during working hours ? Leaves me with some concern.