Credit Suisse has reiterated its 'outperform' rating and 4,000p target price for mining giant Rio Tinto, saying that the business is being handed over to a 'steady set of hands'.Rio Tinto announced on Thursday that it expects to recognise a non-cash impairment charge of $14bn (post-tax) in its 2012 full-year results.These include $3bn relating to Rio Tinto Coal Mozambique, as well as reductions in the carrying values of the firm's aluminium assets (mostly Rio Tinto Alcan but also Pacific Aluminium) in the range of $10-11bn. The group also expects to report a number of smaller asset write-downs in the order of $500m.Credit Suisse said: "Given our valuations for these assets, write-downs would have been expected sometime in years ahead but the year-end audit process seems to have brought forward. We see the Mozambique coal write-down as the lesser anticipated of the two. No change to our valuation or target price."Meanwhile, Chief Executive Officer (CEO) Tom Albanese has stepped down and will be replaced by the head of iron ore, Sam Walsh.Walsh has been with Rio since 1991 and head of iron ore since 2004 "since which time iron ore profits have increased 15 times (price helping of course!) but more importantly he has overseen a near doubling of iron ore production from 107mt to 198mt (attributable) and is responsible for the major Pilbara iron ore expansion from 220mtpa to 360mtpa by 2015 (100% basis) ($22bn) all of which is on budget and schedule," the broker said.Credit Suisse chose to remain upbeat, recommending investors to "look through the noise" of yesterday's announcement."After the market digests this news we think the focus should remain on iron ore prices, project delivery and the larger macro picture, all which remains unchanged following [the] announcement especially given current head of iron ore (80% of earnings/65% NPV) takes over as CEO, share price pressure should be seen as buying opportunity."Shares were up 1.76% at 3,500p by 09:47 on Friday.BC