You can use part of your time for your ACA, the initial 7 month placement can be used towards it as Deloitte have an agreement in place with the ICAEW and it is a period of continuous employment of more than 13 weeks.
However, you must also complete your work experience each year, but this cannot be counted towards your ACA unless you work in an ACA relevant department (i.e not most of Corporate Finance or Consulting) and extend your work experience to at least a 13 week period.