Passing parameter to partial view - Rails 4/postgresql/json

I have a Deal model with a column/attribute called 'deal_info' which is a json column.

It looks like this for example

deal1.deal_info = [ { "modal_id": "4", "text1":"lorem" }, 
          { "modal_id": "6", "video2":"yonak" },
          { "modal_id": "9", "video2":"boom" } ] 
deal2.deal_info = [ { "modal_id": "10", "text1":"lorem" }, 
          { "modal_id": "11", "video2":"yonak" },
          { "modal_id": "11", "image4":"boom" } ]

On my view deal.html.erb, i have:

<%= for deal_nb in 0..@deal.number_of_deals do %>
  <div class="modal fade" id="myInfoModal<%= modal_nb %>" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">
    <!-- render the right modal type -->
    <%= render "layouts/modal_type_partials/mt#{ @deal.deal_info[deal_nb]['modal_id'] }", parameter_i_want_to_pass: deal_nb  %>
  </div>
<% end %>

Above, as you see above, I'd like to pass for each iteration of the loop inside parameter_i_want_to_pass the number of the iteration loop (2nd iteration would be parameter_i_want_to_pass= 2 for example).

On the partial I have:

<div class="modal-dialog">
  <div class="modal-content">
    <div class="modal-header">
      <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span></button>
      <h4 class="modal-title" id="myModalLabel">this is mt4</h4>
    </div>
    <div class="modal-body">
      this is the text: <%= @deal.deal_info[parameter_i_want_to_pass]['text1'] %> 

    </div>
  </div>

I get the following error:

no implicit conversion of String into Integer (on line "this is the text: <%= @deal.deal_info[parameter_i_want_to_pass]")

Actually I even tried to detect more easily the bug by just passing a set number instead of the variable 'deal_nb'

<%= render "layouts/modal_type_partials/mt#{ @deal.deal_info[deal_nb]['modal_id'] }", parameter_i_want_to_pass: 2  %>

But I still get exactly the same error.