NEW YORK (TheStreet) -- Ternium (TX - Get Report), Stillwater Mining (SWC) and Hecla Mining (HL - Get Report) posted hefty gains last week, while Mechel (MTL), Brigus Gold (BRD) and MAG Silver (MVG) declined.

Ternium topped the advancers' list last week, up 9.3%. Nippon Steel, a major shareholder, approved the acquisition of ordinary shares in Brazil-based Usiminas by Ternium, its Argentine subsidiary Ternium Siderar and Brazilian sister company TenarisConfab.

At close last week, Stillwater Mining rose 9%. An analyst at Barclays has maintained an overweight rating on the stock with a price target of $20, indicating 66.5% upside from current levels. After a field trip to the company's recycling facility, the analyst believes that Stillwater's existing operations are on track to achieve full-year targets.

Hecla Mining accumulated 8% at close this past week, while Solitario Exploration & Royalty ( XPL - Get Report) moved up 7.1%, impacted by the price movements of gold and silver. Gold prices were down 0.7% to $1,711.6 per ounce at close last week, while silver prices increased 0.3% to $32.22 per ounce.

Silver Standard Resources ( SSRI) accumulated 7% last week. Meanwhile, Mines Management ( MGN) rose 6% after it was known that the stock is a perfect technical buy, based on all 14 technical indicators, according to

Horsehead Holding ( ZINC) gained 5.9%, tracking the broader market gains. Alexco Resource ( AXU) increased 5.6% after it announced interim results for its 2011 drilling program at the Bermingham property. Previously discovered zones of silver mineralization at Bermingham have been confirmed and expanded. Also, Alexco intersects multiple zones of silver mineralization to 22.2 meters true thickness with narrower intervals to 141 ounces per ton silver over 1.0 meters at Bermingham.

AK Steel Holding ( AKS) added 4.7% at close last week. The company announced last week that it would increase the current spot prices for all its carbon flat-rolled steel products, effective immediately with new orders. For hot-rolled carbon products, base prices are seen up $40, while an increase of $50 is expected for cold-rolled and coated carbon steel products.

Randgold Resources ( GOLD) jumped 4.1% after the company revealed that it expects to keep its cash costs around $700 per ounce for 2011, despite the recent cuts in production guidance. After an upgrade to neutral rating from underperform at Zacks Investment Research, Southern Copper ( SCCO) gained 3.9% last week.

Mechel led the pack of losers, sliding 9.9% at close last week. The company's primary exchange ticker faced a major drop after it suspended work at two mines following complaints to the Siberian branch of Russia's industrial safety watchdog.

Brigus Gold eroded 9.4%, while MAG Silver fell 8% last week.

Coal stocks, Walter Energy ( WLT), Arch Coal ( ACI) and Peabody Energy ( BTU) declined 6.3%, 4.1% and 3.9%, respectively. Last week, Goldman Sachs downgraded the coal sector's rating to neutral from attractive, citing that it is likely to come under pressure of weak demand and lower prices. Goldman has downgraded Peabody to neutral from buy, based on the negative view following the recent acquisition of Macarthur Coal and exposure to the highly volatile global economy.

Eldorado Gold ( EGO) lost 5.7% after HSBC analysts initiated coverage on the stock with an overweight rating.

Mining giants Vale ( VALE) and Rio Tinto ( RIO) wiped out 3% and 2.2% at close last week, respectively.