Absolutely not if you want band 9. You must use natural language, not phrases and sentences you have learned from an academic writing website or book. Never learn sentences to put in your essay. Each essay is written uniquely depending on the topic. Any learned sentences are not counted by IELTS. I strongly suggest you get at least one of my advanced lessons in writing task 2 so you understand not only the techniques but what IELTS is all about in terms of how it functions as a language test: http:///IELTSLizStore
The conclusion is written in one paragraph and its main purpose is to sum up the arguments of the essay, which the author revealed in the topic sentences of the body paragraphs. It summarizes the evidence in support for the thesis statement of the essay and if proved restates this statement. It is a final glance at the presented facts, which lead to a certain conclusion on the essay matter.
The conclusion does not have a set structure and can be written according to the peculiarities of the essay but must always have the mentioned above argument summary analysis.