Version:           1.4.6 (using KDE 3.5.5, Gentoo)
Compiler:          Target: i686-pc-linux-gnu
OS:                Linux (i686) release 2.6.19-gentoo-r2

Although my copy of Kalzium claims to have been translated/localised into British English, the names of the elements aluminium and sulphur are left at their 'American' values.

In particular, aluminium should most certainly be spelt this way (with the 'i'), as it is the IUPAC spelling of the word (it may even be appropriate to spell it 'aluminium' in the en-US localisation).

Whilst 'sulfur' is indeed the IUPAC spelling, if you have 'aluminum' in the US localisation, then it is appropriate to use 'sulphur' in the en-GB variant. Sulphur is definitely the name I have seen used a lot more often than sulfur at university, and according to the Oxford English Dictionary, 'sulfur' is the US-only form:

"sulphur, n.
Forms: 4-7 sulphre, 5-7 sulphure, 5, 7, 9 (now U.S.) sulfur, 6-7 sulpher, (4 sou(l)fre, soulphre, 5 solfre, 6 sulfure, sulfre, sulphyr, 7 sulfer), 5- sulphur. 

    1. a. A greenish-yellow non-metallic substance, found abundantly in volcanic regions, and occurring free in nature as a brittle crystalline solid, and widely distributed in combination with metals and other substances. In popular and commercial language it is otherwise known as BRIMSTONE. (See also SULPHUR VIVUM.) In Chemistry, one of the non-metallic elements: atomic weight 32, symbol S."



Admittedly it is a somewhat controversial topic, given that the QCA in the UK decided that A-level/GCSE syllabuses should use the American spelling for 'consistency', however they really have no business regulating the English language. There is an interesting discussion about the issue here: http://www.worldwidewords.org/topicalwords/tw-sul1.htm

Perhaps it is similar to the issue of -ize and -ise spellings, both of which are said to be correct in British English. Given that the British English KDE uses -ise spellings exclusively, I think 'sulphur' is the way to go. :)