Precious metals prices have gotten hammered over the past several months, and not surprisingly, have brought down the publicly traded miners in tandem.

Copper, gold, and silver are at significantly reduced prices as compared to levels seen a year ago, due to the improving economy and the threat of higher interest rates. Often seen as a 'fear' trade, precious metals tend to rise in times of economic uncertainty.

As a result, miners including Freeport McMoRan (FCX -1.10%), Southern Copper (SCCO -1.66%), and Rio Tinto (RIO 0.43%) have taken a beating over the past several weeks. Are they now attractive stocks to buy?

Enough pain to go around

The global sell-off in precious metals has resulted in depressed profits, and consequently share prices, of these large mining stocks.

Freeport traded as high as $42 per share as recently as October 2012, only to fall to its current level of $31 per share. That means that in just 11months, the stock has lost more than a quarter of its value. Looking further back, the chart is even uglier: Freeport traded above $60 per share at the beginning of 2011.

That being said, Freeport's underlying performance hasn't been as dire as some might fear. Total revenue and operating cash flow declined just 2% and 6%, respectively, during the first half of the year.

Moreover, the company is committed to a concentrated effort to ramp up production. Freeport's $19 billion acquisitions of Plains Exploration and McMoRan Exploration, now completed, are designed to further this strategic priority going forward.

Freeport isn't the only miner in the copper and gold business getting crushed. Gold has lost several hundred dollars per ounce from its recent highs, and copper has dropped to levels not seen in years. That means pain for miners all across the board.

Southern Copper engages in mining, exploring, producing, smelting, and refining copper and other minerals in Peru, Mexico, and Chile. Southern Copper has lost about 25% of its value year-to-date, while the S&P 500 Index has notched nearly 15% gains in that time frame.

For its part, Southern Copper's first half revenue fell 12.5% year over year.  While certainly not good, its results signify a company struggling during a slow-down rather than a more significant business deterioration.

While Rio Tinto has considerable copper and gold exposure, it operates a more diversified mining business. Based in London, the company's reach extends to additional mineral resources such as aluminum, silver, diamonds, coal, and iron ore.

This has allowed Rio Tinto to navigate this tough operating environment admirably.  The company's cash flow from operations actually rose 1% during the first half of the year, which signifies Rio Tinto's ability to effectively manage production and costs.

Rio Tinto traded for $73 per share as recently as the beginning of 2011, and now exchanges hands for just $43 per share.

Miners are now surprising income plays

Global precious metal producers are counted on for growth much more than income from the investing community. However, as a result of their stock prices getting crushed over the past couple years, certain miners offer surprisingly high dividend yields.

Since prices and yields are inversely related, Freeport and Rio Tinto in particular sport nearly 4% yields. While it's true that interest rates have climbed lately, 4% dividend yields remain attractive, considering the 10-Year Treasury Bond is still at just 2.8%.

A 4% yield can effectively blunt the impact of a volatile stock price, as well as provide meaningful downside protection should precious metals plummet further.

A Foolish opportunity among mining stocks?

Prices of precious metals are hard to predict and often swing wildly. As a result, investors may very well experience continued volatility from miners like these three. However, if you can put aside the psychological distress of volatility, there's a long-term buy-and-hold case to be made for well-run mining powerhouses like Freeport McMoRan, Southern Copper, and Rio Tinto.

Companies engaged in precious metals are often best to buy when global commodity prices are in prolonged downtrends. If you believe gold and copper prices are near a bottom, you're being offered bargain-bin prices. Moreover, should volatility continue, you're at least being paid handsomely to wait for the turnaround in precious metals. As a result, long-term, patient investors should consider these mining giants at today's rock-bottom prices.